Hydroponics Q & A Session
January 3, 2009 by Gardener
Filed under Hydroponics
by Dr. Chris Kline
Hydroponics continues to make its way into the mainstream, and with this popularity hydroponics specific retailers are finding their way into towns and cities across the country. Fortunately for those who are not lucky enough to have a hydroponics store nearby there are a wide variety of online resources for equipment, supplies and information, but for those with access to these new retail stores they offer community, support and advice as well as a variety of products to choose from.
This article presents an advice filled interview with Justin C. one of the owners of Sea of Green, a growing hydroponics retailer founded in 1992, with two stores in the Phoenix Arizona area and one in Tucson.
Question: What are some of the most commonly asked questions you get about hydroponics for the home gardener?
Answer: “How does hydroponics work” is probably the most common question. It seems like such a strange and misunderstood concept to many people. Hydroponics means growing plants without dirt, all the food for the plants is in the water instead. People think it is a really complicated process, but if you can measure out teaspoons you can probably figure out hydroponics. In Arizona there is also a buzz about wanting to know if you can do hydroponics outside. The answer is yes, however hydroponics is often about control to get optimum growth and so doing hydro outside just takes a little more consideration.
Question: What are the biggest advantages of hydroponics for the greenhouse gardener?
Answer: The biggest advantages are more plants in a much smaller space, ability for total environmental control, no need for toxic pesticides, and speed of growth.
Question: What are some of your favorite hydroponics systems at various price breaks (low, medium and high) and why do you like these systems?
Answer: Bucket systems are the lowest cost and often the most successful units for anyone interested in trying something like a single pepper plant or an assortment of herbs. This system generally consists of a five gallon bucket with a pot insert and a drip collar on top that recirculates water 24 hours a day. The system is easy to setup, requires limited maintenance and is relatively inexpensive. A middle range system would be something more automated like an ebb/flow type system on a timer. This system consists of a reservoir that usually sits underneath the tray supporting the plants. Water floods the tray several times a day, per the timer, and then drains back down to the reservoir. This system is more aggressive then a bucket system and give growers a little more flexibility to grow more then one plant. Aeroponics is the most expensive type system where the roots hang in the air with nothing around the roots except the spray of nutrient solution with a high power pump. This is the super charged system, but this system is the least forgiving. I would never recommend it for the novice, but rather for the experienced hydroponics gardener who wants to get twice the yields in about half the time.
Question: What are some of the biggest mistakes home gardeners make with hydroponics?
Answer: Hydroponics is a skill like anything else and sometimes it is necessary to tinker with a system to get it dialed in for the aggressive growth that is possible with hydroponics. Patience is very important and if anyone sticks with it even a few months they can be very successful. It is also a very experimental hobby and no one person has all the answers. Everyone has a situation that is a little different and everyone’s setup is different. Besides small errors like pH, or over nutrient levels, people often rely on simple answers from books that don’t account for a grower’s particular situation. Personal experience is the only way to get it right.
Question: Can you give us a few of your favorite tips for home hydroponics?
Answer: Start simple, but don’t overlook all fundamental parts of plant growth including light, CO2, temperatures, etc. Keeping a grow diary helps to keep track what you did right or wrong. Check pH! Especially if using chemical nutrients over organic nutrients. Organic nutrients are easier to use, but chemical nutrients can give faster growth. And be patient!
Question: What do you see in the future of hydroponics for the home gardener?
Answer: It is taking off as a popular form of gardening with more people getting into it every year. The thing I love the most about this industry is that you are constantly learning new things and the innovations never cease. For the home gardener it is a relatively new concept, maybe 50 years old, or so. But the expansion of the industry is reducing the cost and simplifying the methods so that even novice gardeners will succeed with hydroponics. The growers who come to us at the store are not in one time and that’s it. We build a relationship with our customers and see them coming in every week, year after year, learning from us as we learn from them.
Hopefully the trend towards more local hydroponics retail outlets will continue and this may even push the traditional garden centers to include more resources for indoor, greenhouse and hydroponics gardening. GG
Dr. Christopher J. Kline is a master gardener and writer living in Paradise Valley Arizona. He is an editor for The Ultimate Sunflower Site www.SunflowerOcity.com and a columnist for Garden and Greenhouse Magazine www.gardenandgreenhouse.net. You can reach Chris at CKline72@Cox.net
How to Build a Small Drip Hydroponics System
January 3, 2009 by Gardener
Filed under Hydroponics
by Dr. Chris Kline
Drip hydroponics systems are easy to build and maintain and can be used to grow herbs, tomatoes, peppers or a combination of each.
Things You Need
- Inexpensive plastic pots, one 12 inch, one 10 and one 8 inch.·
- Two-Three plastic 14 inch pot saucers
- Submersible hydroponics water pump (approximately 160GPS)
- Tubing to fit the pump (approximately 3 feet) and one T-connector
- Expanded clay growing medium to fill two smaller pots
- Small air pump with two feet of tubing and air stone
- 100% silicone sealer (small tube)
- Hydroponics grow and bloom nutrients solutions
- pH test kit and pH down (possibly pH up depending on home water chemistry)
Tools
- Drill with 1/8th and 3/4th bits
- Utility knife
Step 1
Seal the hole in the bottom of the largest pot that will serve as the system reservoir. To do this, turn the pot upside down and use 100% silicone sealer to glue a small piece of plastic over the hole. Cut the plastic piece about twice as large as the hole. Any flat thin plastic will do. One easy to find source is to cut these out of clear plastic plant saucers. Next, turn the pot back over and fill the hole inside completely with silicone and even a little extra for a good seal. This should dry 6-8 hours before water is added to the system.
Step 2
Install the pumps and feed tube. Connect the tubing to the submersible hydroponics pump. Generally the tubing will fit tight on the pump spout and a hose clamp is not necessary, but if needed, use a hose clamp to make sure the feed tube stays attached to the pump. Connect the air tube to the air stone. Set the air stone with a rock on top to keep it down and the submersible pump in the bottom of the reservoir.
Step 3
Use 2-3 14 inch saucers for the reservoir lid because one is not strong enough to hold the weight from the growing pots. Set the saucers on top of one another and drill a hole two inches in from the back just large enough to accommodate the feed tube and another just large enough to provide passage for the submersible pump cord and air line. Use a utility knife to cut an opening in the front of the bottom saucer 3×4 inches. This will allow for viewing the reservoir level and adding nutrient solution. Cut a hole ¼ inch smaller all around for the top saucer. Glue the pieces that were cut out of each saucer together and this may be used to cover the opening when not needed. Insert the feed tube back hole and the air tube and submersible pump cord through the back hole. Cover the reservoir pot with the saucers as a lid.
Step 4
The pots should have drain holes in them already. If not, drill drainage holes large enough to allow water to drain through, but smaller than the size of the expanded clay growing medium in both the 8 and 10 inch pots.· Drill a hole in the back large enough to accommodate the feed tube, thread the tube through, and set the 10 inch pot on top of the reservoir lid.
Step 5
Fill the 10 inch pot with expanded clay growing medium to within ½ inch from the top. Thread the feed tube through the hole in the back of the 8 inch pot and set the pot on top of the growing medium in the 10 inch pot. Cut the feed tube at the top of the top pot. Hold the feed tube by one side of the pot and fill the pot with growing medium to a couple inches below the top being careful not to allow any medium to fall into the feed tube.
Step 6
Cut a piece of the water tubing to make a 6 inch circle and connect the ends together with the T connector. Lay this circular hose on a flat surface with the T-connector opening facing up. Drill 1/8th inch holes every half inch around the circle. Connect the T-connector to the feed tube in the top pot and fill the pot the rest of the way so that the drip circle sits on top with medium almost covering.
Step 7
Use a clean bucket or other container to mix nutrient solution. If possible use RO filtered water or some other source of filtered water. Check the pH of the water and adjust accordingly using pH up or down to a level of 6.5. Most often pH will need to be lowered. Add hydroponics grow formula to the water per the manufactures directions. Fill the reservoir with nutrient solution and plug in both the air and water pumps.
Planting
Seeds can be started in small peat pots, peat pellets, or various forms of soil-less seed starting cubes or plugs. The small plants can then be transferred to the unit by burying them with their seed starting medium in the expanded clay medium. With larger plants like tomatoes or peppers this system works well with one in the top growing pot and 2-3 in the lower one. For tomatoes three foot plastic poles can be inserted in the growing pot on either side of each plant for staking. The system can be placed on a covered patio in a sunny location or indoors if grow lights are used.
Maintenance
Start with a full reservoir. When the solution is down to just above the pump, add a gallon of pH adjusted water to the reservoir and run the system for five minutes. Unplug the water pump and disconnect one side of the drip tube from the T-connector and place the end in a large bucket. Plug the pump back in and drain the system until the pump just starts to suck air. Unplug the pump immediately and do not let the pump suck air. Use this water to water soil based plants. Fill the reservoir back to the top with pH adjusted nutrient solution. Use a grow solution until plants begin to flower and then switch to a bloom solution. Reconnect the drip tube to the T-connector and plug the pump back in. Every three months, or sooner if needed, change the air stone and clean the intake components of the submersible pump. After each growing season it is a good idea to rinse the growing medium and spread it out to air dry.
Building a small hydroponics system is a rewarding and productive experience and they certainly add beauty to any garden or indoor setting.
Dr. Christopher J. Kline is a master gardener and writer living in Paradise Valley Arizona. Chris is a member of the Garden Writers Association and a columnist for Garden and Greenhouse Magazine http://www.gardenandgreenhouse.net·
Contact: CKline72@Cox.net
How to Keep Hydroponics Systems from Smelling Bad
January 3, 2009 by Gardener
Filed under Hydroponics
by Dr. Chris Kline
One common complaint about hydroponics is the smell that often results, but with a little care and knowledge, a well run hydroponics system doesn’t need to end up becoming a slimy, smelly mess and odor problems can be easily avoided.
Tip #1 – Keep the system as free of organic materials as possible
Nutrient solution problems are often the cause of bad smell in hydroponics systems.
Bad odors can be both strong and persistent and are a result of bacteria metabolizing proteins which releases amines and sulfur containing organic molecules into solution. Microbial growth in the nutrient itself is a result of having organic materials in the system somewhere (fungi etc need organic matter to feed on). Because of this, it is important to avoid introducing unnecessary organic material into the nutrient solution or growing media. Organic matter may have come from large amounts of old rotting root systems or vegetation from a previous crop or use of organic growing media. Take steps to avoid these problems by using non-organic starting medium for starting plants to be added to the system and a non-organic growing medium in the system. Between crops replace or clean the growing medium to remove unwanted organic matter. Use a dark reservoir and keep it covered to keep light and foreign organic matter out.
Tip #2 – Take Steps to Maintain a Microbial Equilibrium in the System
The microbial species which produce the bad smells, slime and other undesirable problems are not to be encouraged, but there are beneficial microbes that can be added and encouraged in the system. First, start with a clean, sterilized water source, add in the nutrients, and then inoculate the nutrient solution with a mixture of beneficial microbes (see product list below). This gives the beneficial microbes a head start and results in a healthy system where any pathogens should be suppressed before plant damage occurs. The following are some well know products that contain beneficial bacteria:
Beneficials Bio-Link PlusTM is organic and contains naturally occurring organisms, beneficial Microbes and Fungi that aid in the natural process of plant growth and development.
Dr Hornby’s Piranha PowderTM and Voodoo JuiceTM. Voodoo Juice colonizes the root zone with friendly bacteria. Piranha Powder colonizes the root zone with 26 different beneficial fungi. These include 8 species of Trichoderma (which encourage root growth and protect against fungal pathogens) and 18 species of endo and ecto micorrhizal (which help break down nutrients, aid structure and improve uptake).
Ell-Gro Ag-Bact Water PolishTM consists of thirty varietel aerobic (pro-biotics) bacteria. These pro-biotics are cultures in a registered NATA micro-biological laboratory using a recipe compiles by agricultural scientists.
FlourishTM works symbiotically with native microbes to maximize the sub-surface decomposition of organic plant and animal materials and fertilizers making their rich organic nutrients that plants have grown to love almost immediately available.
General Hydroponics SubCulture is a blend of fifty-two soil microorganisms that will increase vitality and yield in all plants. Whether in soil or hydroponics, the proprietary mixed blend of bacteria, actinomycetes and trichoderma fungi colonize in the root zone and media to form a symbiotic relationship with the plant.
Tip #3 – Use Only Nutrients and Additives that are Specifically Designed for Hydroponics
Avoid the use of organic fertilizers which are used and designed for soil based systems. Many of these rely on boosting the population growth of microbes in the soil which in turn break down organic matter, releasing nutrients. Many of the organic compounds are not fully mineralized and putting these soil based organic fertilizers (such as fish emulsions) into a hydroponics system in large quantities can have rapid and unpleasant results.
Tip #4 - Keep the Nutrient Solution Well Oxygenated
Start with a clean system and keep the nutrient well oxygenated. This helps swing the equilibrium in favor of the beneficial microbes and provides oxygenated solution to the plant roots. Air pumps are now very inexpensive and should be used with an air stone to add oxygen to the nutrient solution. Plant only healthy seedlings into the system in non organic starting media and remove any sick or stressed plants as soon as they are noticed, making sure to get most of the roots.
Tip #5 - Flush the System and Replace the Nutrient Solution Often
It is possible to test nutrient solution often and maintain proper pH and nutrient levels, but it is beneficial and much easier to replace the solution every week or at least every two weeks. Set the system up so a water pipe can be easily opened to drain the system. Plan to drain the system when the reservoir is already low. Drain the solution into a watering can until the pump starts to draw air. Use this nutrient rich water to water soil based plants. Add a gallon or two of pH adjusted water to the system and run the system for five minutes to flush. Drain the system again and then fill with pH adjusted nutrient solution and beneficial microbes.
Tip #6 - Consider Ozone Generators and Carbon Filters
Ozone Generators and Carbon Filters are no substitute for the general hydroponics practices discussed in the previous tips and they may very well be unnecessary for odor control if these tips are diligently applied. They may however have benefits beyond odor control that are worth considering. For example, The Black Max Ozone SystemTM claims to purify the water by injecting ozone directly into the holding tank or the nutrient reservoir. In the water, excess ozone constantly breaks down into oxygen which super oxygenates the nutrient solution, promoting rapid healthy root development, plant growth and higher yields. Carbon Filters are probably the best way of removing odors from any area. Charcoal has long been recognized as one of the best vehicles for air filtering and different size filters are available for different sized growing rooms. Carbon Filters are easy to install and operate.
By consistent application of the above tips a Microbial equilibrium can be created in the hydroponics system that will not only have limited undesirable odors, but will consistently produce better harvests.
Dr. Christopher J. Kline is a master gardener and writer living in Paradise Valley Arizona. Chris is a member of the Garden Writers Association and a columnist for Garden and Greenhouse Magazine http://www.gardenandgreenhouse.net. You can contact him at CKline72@Cox.net
How to Hand Pollinate Indoor Gardens
January 3, 2009 by Gardener
Filed under Hydroponics
by Dr. Chris Kline
Some plants need a helping hand for good pollination when grown indoors or in a greenhouse, but it is easier than one may think and you will only need some Q-tips and/or small paint brushes.
Vegetables and other plants can be hand-pollinated by taking a Q-tip or small paint brush and transferring the pollen from the male flower to the female. Male flowers will bear stamens and female will bear pistils (the female always has a small fruit on the end). Make sure to clean the brush or use a new Q-tip when pollinating more than one type of the same plant. Hand pollination is necessary with plants that have a male and female flower like squash, cucumbers etc. This method is needed if growing vegetables indoors or in a controlled environment like a greenhouse.
Some plants need less help than others to pollinate indoors. All that is needed to help pepper and tomato plants is to gently shake the plant every couple of days to advance pollination. Some self pollinators like peas, beans and lettuce do not need any help to pollinate indoors.
Poor production from indoor and outdoor vegetables is often caused by over fertilizing with high nitrogen fertilizers rather than poor pollination. Fertilizers high in nitrogen are desirable during the growth cycle, but once the plants are ready to flower it is important to switch to a fertilizer higher in phosphorus and potassium. These fertilizers generally have the word “bloom” in their name and should have a ratio that favors the last two numbers over the first, a fertilizer with a 1-2-2 ratio, for example.
Dr. Christopher J. Kline is a master gardener and writer living in Paradise Valley Arizona. Chris is a member of the Garden Writers Association and a columnist for Garden and Greenhouse Magazine http://www.gardenandgreenhouse.net. You can contact him at CKline72@Cox.net
Hydroponics Growing Medium - Getting Down to the Nitty Gritty
January 3, 2009 by Gardener
Filed under Hydroponics
by Dr. Chris Kline
Growing medium is anything that a plant can grow in, and dozens, if not hundreds of forms exist. This article will focus on various popular forms of growing medium that are suitable for use in hydroponics or plant starting and will introduce a very promising relatively new medium. It is important to understand that it is difficult to select one best medium for all purposes. Commonly used growth mediums each have advantages and disadvantages and may even be combined to form a more perfect growing environment.
Functions of Growing Medium
Growing mediums provide support both physically and biologically. Physical support is provided by allowing the plant to grow its roots through the medium to hold itself in place. Biological support is provided by the medium’s ability to hold nutrients, water and air that the plant needs and its ability to release carbon dioxide. In soil based gardens, the medium (soil) also supports other types of life. Microorganisms and insects live in the soil and they in turn aid plant life by helping to decay organic material, adding structure and nutrients to the soil. Each commonly used growing medium has advantages and disadvantages and may be more suitable for use in one hydroponics system than another.
Soiless Mix
Most of the time products sold as “potting soil” are really not soil at all. They are soilless mixes containing a varied assortment of ingredients. The most commonly found components are Sphagnum moss, Perlite and Vermiculite. Unlike most hydroponics growing medium, soilless mixes are usually considered organic and are frequently used for container gardening, wick systems and non-recovery drip systems. Most of these mixes have some very fine particles that can clog pumps and drip emitters making them unsuitable for recovery systems. The best soilless mixes have great wicking action and retain water and air well, making them suitable for semi-hydroponics methods and container gardening.
Coconut Fiber
Coconut fiber has become a very popular growing medium, and for good reason. For those looking for a totally “organic” growing medium that offers top performance in hydroponics systems, coconut fiber may be the best choice. Compared to rockwool (discussed below) it maintains a larger oxygen capacity and has superior water holding ability which is a real advantage for hydroponics systems that have intermittent watering cycles. Unlike most synthetic mediums, coconut fiber is believed to be high in root stimulating hormones and offers some protection against root diseases including fungus infestation. A common formula popularized by Dutch growers consists of a mixture of 50% coconut fiber and 50% expanded clay pellets. This mixture is particularly suitable for continuous drip systems where water holding ability is not as big a concern and more oxygen holding capacity is desired. There is some concern that all coconut fiber products are not created equally, so care should be taken to purchase a premium blend.
Perlite and Vermiculite
Perlite is often used as an additive to soilless mixes or soil to increase aeration and drainage and may be used by itself in continuous flow hydroponics systems. Because it does not retain water well, it is often combined in a 50/50 mixture with vermiculite. Unlike perlite, vermiculite retains water well, perhaps too well to be used by itself. Both vermiculite and perlite are inexpensive, and combining the two makes a very popular and effective medium for drip and ebb and flow systems. Vermiculite and perlite must be rinsed thoroughly before use and care should be taken not to inhale the dust as it is hazardous to ones health. It is important to buy horticultural grade products, as those produced for other purposes often do not have a stable PH and will make maintaining proper pH in the system very difficult.
Expanded Clay
This product has several nick names including: hydro corns and grow rocks and is an extremely good growing medium. The pellets are great for ebb & flow systems or other systems that have frequent watering cycles. Expanded clay dos not retain much water so it works best in continuous flow systems or mixed with other mediums to increase water retention. One drawback is that expanded clay pellets are rather expensive, but fortunately they are one of the few kinds of growing medium that are easily reusable. Between crops they can be recycled by removing all the old roots and then sterilizing with a 10% bleach and water mix.
Rockwool
Rockwool is one of the most popular growing mediums. It was developed for gardening in Denmark and is used extensively for continuous drip hydroponics systems. Rockwool comes in many shapes from one inch starter cubes to large three foot slabs which make it quite a very versatile growing medium. Rockwool holds water well and unless it is sitting directly in water it holds enough air to supply roots with plenty of oxygen. Rockwool has a few notable disadvantages. Like perlite and vermiculite the dust is hazardous if inhaled. It also must be pre-soaked for 24 hours prior to use. Perhaps the most notable problem is that rockwool has a high pH which requires that the nutrient solution pH be lowered more often to maintain correct growing pH levels.
Sure To Grow MediaTM
Sure to grow media is a relative newcomer that was patented in the late 90’s. It resembles some kind of cloth or foam material that could be used for quilting or crafting, but make no mistake about it; this is a serious growing medium. One of the greatest advantages of Sure to Grow Media is that it comes in a variety of shapes and sizes and if needed it can be cut to fit any application. It was designed for ease of use for hobbyists, but is also finding favor among commercial growers seeking the efficiencies that it provides, because in the plant business, a more efficient grower is a more profitable grower. There is virtually no setup time. It wets instantly, has great aeration and water retention, is pH neutral and sterile, clean and hygienic. For larger growing operations this product offers a marked advantage over most other mediums as it can be rolled out into any size gutter system and rolled back up for change out between crops. After using this medium along with others it is hard not to come back for more, as it just makes setting up a hydroponics system so effortless compared to most other growing mediums, and this same advantage is enjoyed again when it comes time for crop changeover. For information on Sure To Grow products visit www.suretogrow.com.
Dr. Christopher J. Kline is a master gardener and writer living in Paradise Valley Arizona. Chris is a member of the Garden Writers Association and a columnist for Garden and Greenhouse Magazine http://www.gardenandgreenhouse.net. You can contact him at CKline72@Cox.net
Growing Tomatoes Hydroponically
January 3, 2009 by Gardener
Filed under Hydroponics
by Dr. Chris Kline
Growing Great Hydroponic Tomatoes
There has been a great deal of money spent researching and growing hydroponic tomatoes commercially, so it makes sense to follow the lead of the commercial growers. What are the commercial growers using for hydroponic tomatoes? By and large, most commercial growers are using various forms of drip irrigation systems and growing tomatoes in either rock wool slabs or perlite.
The process is similar regardless of the container or growth medium used. A drip line is used to supply nutrient solution, on either a continuous or intermittent basis, to the base of the plant. Approximately 1-1.5 inches of nutrient solution is maintained in the bottom of the growing container which is generally around 7 inches deep. Adequate drainage is supplied to allow all but the 1-1.5 inches of nutrient solution in the bottom of the growing container to return to the nutrient solution reservoir where it can be re-circulated. Nutrient solution is tested/maintained and periodically flushed and replenished. Flushing the system with pure water periodically also helps to leach excess salts from the growing medium.
Success can be had, particularly with smaller varieties of tomatoes using high tech aeroponic systems and many home growers have good results with flood and drain systems; but in keeping with what is being done for commercial production, the most common method employed for large plants in home systems generally involves some type of drip irrigation. In this fully automated, re-circulating system nutrient solution is pumped from a reservoir, fed to the plants through drip emitters and allowed to drain back to the reservoir by gravity.
There are many good options for starting this type of growing system in the home or small farm garden.
Build Your Own System
Fortunately for those on a budget, or who just want to have a more intimate relationship with their growing system, there is some excellent guidance available for building your own system for growing hydroponic tomatoes. A simple online search on “build your own hydroponics system” yields useful links such as this one: http://members.mailaka.net/norm34/building3.html where you can get detailed illustrated plans for building what they call the “Poor Man’s Dutch Pot System” for free, or you can go to www.howtohydroponics.com and spend a few dollars for “How to Hydroponics” which contains detailed plans for several relatively easy to build systems.
Ready to Grow Top Feed Drip Systems
R & M Supply has a good system that is available as a single pot unit or as a system with eight pots connected to a shared nutrient reservoir. Visit http://www.randmsupply.com/.
Tower Drip Systems
There are several companies marketing tower growing systems. These systems use some sort of vertical arrangement where the nutrient solution can flow from the top set of growing containers through each level and finally to a reservoir at the bottom of the tower. These systems are worth looking into and may be particularly valuable where garden space is at a premium. When shopping for such a system, be aware that some towers are NFT Systems and not designed for growing in medium. Also, some of these systems are not designed with a re-circulating pump and reservoir and require some means for supplying adequate irrigation to the top pots and dispensing of, or re-circulating runoff from the bottom. Two companies offering vertical growing systems are:
Smart HydroGro Tower http://www.shopsmartorganics.com/
Hydro-Stacker http://www.hydrostacker.com/
Starting Tomato Plants
Many hydroponics growers prefer to start plants from seed to avoid any possible pest or disease contamination from nursery stock. Rockwool cubes are a good choice for seed starting rather than using organic substances like peat that will then decompose causing possible problems when placed in the growing medium. The one inch rockwool cubes can be arranged in standard nursery trays with pre-fit plastic domes, or any suitable tray can be covered with cellophane kitchen wrap to help maintain a mini-greenhouse environment for seed germination. When using rockwool for seed germination, or as a growing medium, make sure to presoak with water adjusted to a pH of 4.5 prior to planting. It is important to provide adequate natural or artificial light to your seedlings as soon as they sprout to avoid lanky, weak plants. Once sprouts have bolted in search of light, the process cannot be reversed and week adult plants will result. Generally, in a couple weeks the sprouts will be showing their first true leaves and will be ready to be transferred into their permanent home in the growing medium.
Growing Mediums
Commercial hydroponic tomato growers use Rock Wool more then any other growing medium and Peralite is probably a close second. But great results are also possible using other forms of medium including various brands of expanded clay, pine bark, coconut coir or combinations of the above. There are also some new growing mediums coming on the market that may offer some advantages and are definitely worth a look. One such product is Sure to Grow http://www.suretogrow.com/.
Regardless of the technique used to grow tomatoes, several factors are important for successful harvests.
Light Considerations
The lighting that tomatoes receive will have a significant impact on growth and fruit production. Many people mistakenly believe that because tomatoes do well when days are long that they prefer intense light. On the contrary, particularly in the southern latitudes, and summer months in all latitudes, tomatoes do better with partial shade and/or defused light. When tomatoes are grown outdoors, or in a greenhouse setting, ideally partial shade should be provided after noon when the sunlight is most intense.
Tomatoes will have maximum fruit production with 16-18 hours of light, but they may also do best with 8 hours of total darkness each day. If you are growing tomatoes in a greenhouse for year round production or an extended season, or indoors under entirely artificial light, 16 hours of light each day is a good target. The quality of artificial light is as important as the quantity. Tomatoes do best if supplied with full spectrum lighting throughout their growth cycle. If you plan on providing artificial light, search for lights that provide both blue and red spectrum light. The following links may be helpful in locating high quality MH/HPS Dual Spectrum Lights:
http://www.specialty-lights.com/
www.greenhousecatalog.com/garden
www.plantlightinghydroponics.com
Nutrient Solution Considerations
Two important factors concerning the nutrient solution are pH and (EC) electrical conductivity. It is critical that water used to mix nutrient solution for tomatoes be adjusted to a pH of 5.8-6.3. Once the correct amount of pH up or pH down solution needed to adjust ones tap water is determined by using an inexpensive pH test meter, this same amount can be used each time pH adjusted water is needed. EC measures the total dissolved solutes in the solution and gives an indication of the nutrient level. The optimal range for tomatoes is 2.0-3.5. Quality nutrient solutions will have mixing instructions that will provide the proper nutrient level. Generally best results can be had by using a quality growth formula until the plants near the flowering stage and then switching to a bloom formula.
For small systems it is recommended that the nutrient solution be changed and the system flushed with pH adjusted water each week. This is accomplished by draining the reservoir of used nutrient solution, running pure pH adjusted water through the system and then draining this and adding freshly mixed nutrient solution. The used nutrient solution and the leaching water can be used to water other soil based plants. This process will help to leach excess salts from the growing medium and insure proper pH and nutrients are maintained.
Temperature
Tomatoes are a warm weather plant and do not do well when the air temperature dips below 50 degrees (Fahrenheit). Optimum temperature for tomatoes is 70-85 degrees during the day and 65-70 at night. In greenhouse settings these optimum temperatures can be maintained or tomatoes will do quite well at a constant 75 degrees. Many outdoor growers like to start plants inside several weeks before outside temperatures are optimal to get a jump on the season. This is a good practice, but care must be taken not to set plants outdoors too soon. Plants subjected to cold conditions may never fully recover and be poor producers.
Tomatoes are very well suited to hydroponic growing, particularly using top feed drip systems. For soil based gardening enthusiasts wanting to give hydroponics a try, starting a small hydroponic tomato growing system may be just the thing to wet the appetite this season.
Dr. Christopher J. Kline is a master gardener and writer living in Paradise Valley Arizona. Chris is a member of the Garden Writers Association and a columnist for Garden and Greenhouse Magazine http://www.gardenandgreenhouse.net. You can contact him at CKline72@Cox.net
Nutritional Supplements for Hydroponics and Soil Based Gardens
January 3, 2009 by Gardener
Filed under Hydroponics
by Dr. Chris Kline
Just like animals, plants require a wide variety of nutrients, in addition to pure water, to function at their best. For soil based gardens the goal should be to have soil that not only performs the mechanical functions of providing gas exchange, drainage and support, but that helps to provide the nutrients needed for healthy plants. Well developed compost can provide nutrients that are hard to replicate with other fertilizers and supplements. That said, regular fertilization with quality products can certainly increase plant growth and production. With hydroponics, all plant nutrients must be supplied in the nutrient solution or through foliar feeding. This article will discuss some promising nutritional supplements for plants that go beyond the primary nutrients and list a few recommended products in each category.
Micronutrient Supplements
Fortunately, the better fertilizer companies have added micronutrients to their products in addition to the three primary plant nutrients: nitrogen, phosphorous and potassium. For those not using fertilizer, or using a blend that does not contain micronutrients, there are some good products formulated to prevent and correct micronutrient deficiencies. Micronutrients can do some great things for the soil including influencing proper soil pH, improving soil structure and water retention and positively influencing the level and activity of beneficial soil microorganisms. They also aid plants to better use primary nutrients. Because of these benefits, and particularly if one has experienced problems associated with micronutrient deficiencies like blossom end rot or tip burn, it may be good insurance to experiment with micronutrient supplements. Two possible products are:
Botanicare Cal-Mag Plus
A plant supplement designed to help with calcium, magnesium and iron deficiencies in nutrient fertilizer programs and hydroponic nutrient liquid concentrated formulas. It prevents blossom end rot in plants such as tomatoes and peppers and tip burn in lettuce by serving as a catalyst for the major elements to work in symbiosis with one another. For additional information visit http://www.americanagritech.com/
Technaflora MagiCal
An enriched formulated blend of magnesium, calcium and iron, that promotes plant growth for both soil and soilless gardens. Incorporated in regular feeding programs it increases flower bud absorption and improves the nutritional quality of plants while correcting nutrient related plant deficiencies. In addition to correcting nutrient deficiencies, it also accelerates protein syntheses, maintains high starch content in crops, improves the density of fruit and the production of essential oils, creates lush and greener foliage, and maintains a healthy root system. Designed for universal application, it is for gardens that require bolstered levels of magnesium and/or calcium. For additional information visit http://www.technaflora.com/.
Vitamins
B Complex vitamins have been shown to help plants overcome stressful growing conditions, increase nutrient uptake and increase disease resistance. Some formulations may also contain other vitamins, amino acids and minerals. The use of B vitamins may be of most benefit when transplanting and/or during early season root formation. Two possible products are:
Technaflora Thrive Alive B-1
Stimulates rapid and lush vegetative growth, and will ensure the success of floral crops by promoting flowering during blossoming. It contains vitamins and nutrients, which are cultured in sea kelp. It facilitates root development for both cuttings and established root systems, while protecting plants from transplant-related shock. Safe and easy to use, it can be applied as a soil drench, rejuvenator, or as a foliar spray. For more information visit http://www.technaflora.com/.
VitaMax™ and VitaMaxplus™
A specially formulated to encourage better root development, larger buds, blooms, fruits and flowers. It contains essential macro and secondary nutrients to help increase plant development at the blooming and fruiting stages and to reduce plant stress during transplanting, inclement weather etc. VitaMax Plus™ has the same stress-relieving properties as Vitamax™ plus a slightly higher concentration of ingredients making this product an ideal supplement to use during heavy flowering. For more information visit http://www.getgreenstar.com/.
Silicon
Silicon (Si) is abundant in most soils. It is readily taken up by plants and is often present in relatively high concentrations in plant tissues. The beneficial effects of adequate Silicon may include decreased susceptibility to fungal pathogens (and insects), increased stress resistance, improved nutrient uptake and increased growth. One possible product to consider is:
Botanicare Silica Blast
Helps strengthen plant tissue helping plants flourish in adverse environmental conditions such as heat, drought, and frost. It is designed for use in container gardens or soilless hydro-gardening applications. For more information visit http://www.americanagritech.com/.
Kelp (Seaweed)
In addition to being a good source of organic nitrogen and potassium, kelp contains vitamins, minerals, carbohydrates, enzymes, amino acids and growth hormones necessary for optimum plant growth. Kelp stimulates soil bacteria to release plant nutrients already found in the soil and contain cytokinins which directly affect the ability of plant roots to absorb nutrients. It is believed to increase a plant’s stem strength helping the plant handle the stress of wind, rain, drought, high temperatures, and frost. Several possible products to consider are:
Maxicrop Liquid Seaweed
Our basic pure seaweed extract’s natural growth stimulants initiate cell growth and cause vigorous growth of both root and stem. The trace elements that Maxicrop Liquid Seaweed contains are important at this stage—in enzymes, as activators of enzyme systems, and as stimulants. For additional information visit http://www.maxicrop.com/.
Neptune’s Harvest Kelp Meal
Neptune’s Harvest Organic Kelp Meal is suitable for all crops and applications, and can be mixed with most soil conditioners and fertilizers. It can also be incorporated into potting soils, seed and transplant beds, as well as composting material. For additional information visit http://www.neptunesharvest.com/.
Neptune’s Harvest Seaweed Plant Food
This is an organic product containing over 60 naturally occurring major and minor nutrients and amino acids. Its growth promoting substances (Auxims, Cytokinins, Gibberellins) enhance plant development, color and vigor. For additional information visit http://www.neptunesharvest.com/.
Technaflora B. Seaweed
An optimal growth stimulant for all your plants made from 100% pure kelp (Macrocystis integrifolia) and is an organic way for growers to supplement their current feeding programs. It is concentrated, and must be diluted with water for use in irrigation solutions or as a foliar spray. Ideal as an additive for organic tea mixtures, it is also a superior soil tonic, and can be added to the hydroponic reservoir. For additional information visit http://www.technaflora.com/.
Humic and Fulvic Acids
This is a big part of the good stuff that composting aims to develop. These complex molecules are formed as organic matter decays, and occur naturally in soils, peat, oceans and fresh waters. Humic acids are the primary extractable component of humic substances. Fulvic acids are also extracted from humic substances and may be more plant active than humic acids due to their higher oxygen content and abundance of carboxyl groups. Humic acids enhance the nutrient richness of soil and they are believed to increases the permeability of plant membranes promoting the uptake of nutrients resulting in stronger, healthier, better producing plants. For more information on applicable products visit these websites:
Blackjack Liquid Humic Acid and Golden Humic Acid Extract
These products are a proprietary premium blend of 100% humic minerals from leonardite in an aqueous base. They are fast acting and have a guaranteed source of phosphorus as available phosphate P205 (0-2-0). The products may also have a natural source of over 70 plant-derived trace elements, carbon, enzymes and amino acids that contain naturally occurring organically infused microscopic soil known as nano-nutrients that are not listed or guaranteed on the label. For more information visit http://www.blackjacksoil.com/.
General Hydroponics Diamond Nectar
Diamond Nectar applies the magic of the smallest available humic acids to nutrient rich hydroponic environments by grabbing these nutrient minerals and transporting them into plant roots for faster growth and higher yields. It enhances your nutrients in order to optimize the health of your plants and the quality of your crops. For additional information visit http://www.generalhydroponics.com/.
General Hydroponics Rare Earth
Rare Earth is derived from ancient seabed deposits of pyrophylitic clay that are blended with fulvate ore. By slowly releasing silicon, humates, and organic rare earth minerals, Rare Earth allows a crystal matrix to develop within growing plant tissue that protects the plant from heat stress and nutrient extremes by generating a protective silicon shield. This also deters fungal disease and reduces susceptibility to insect damage by “hardening” the plant. Use Rare Earth by blending it with rooting media, and either top-dressing around the plant stem or adding it directly to nutrient solutions. For additional information visit http://www.generalhydroponics.com/
Neptune Harvest’s Super Humate
Super Humate contains vital elements for healthy soil in an easy to apply liquid form. It provides valuable plant elements, holds water in the soil, feeds the living organisms in the soil, and releases locked-up nutrients for plant growth. For additional information visit www.neptunesharvest.com.
Technaflora Concentrated Liquid Humus
This product is a natural and organic source of concentrated essential nutrients, vitamins and trace elements. It is a 100% organic solution of 15% technical humic acids extracted as salts from a soft coal called leonardite. It increases the permeability of plant membranes and the buffering capabilities of the medium, promoting the uptake of nutrients. With the systematic application of Liquid Humus, the results are healthier, lusher plants with faster growth, more vigor and larger yields.. For additional information visit http://www.technaflora.com/.
The field of human health supplementation is full of products and claims of increased performance and plant nutritional supplementation is not far behind. With the supplements discussed in this article and others, it may be worth a side-by-side experiment to see if the addition to ones individual soil or nutrient solution has a positive impact on plant growth and performance.
Dr. Christopher J. Kline is a master gardener and writer living in Paradise Valley Arizona. Chris is a member of the Garden Writers Association and a Senior Staff Writer for Garden and Greenhouse Magazine. You can contact him at CKline72@Cox.net
Easy Lettuce Growing with a Raft Aquaponic System
January 1, 2009 by Gardener
Filed under Gardening Knowledge, Hydroponics
by Dr. Chris Kline
Easy Lettuce Growing With a Raft Aquaponic Garden
If you love salads and have always wanted an easy way to grow them at home this article is for you. If you have been put off starting your own system of hydroponics at home because you think it’s too complicated, this article will offer you an easy method for getting started with simple hydroponics while producing some great salad greens. A homemade hydroponics system can be very simple and perhaps the simplest system is what is called a water culture raft system. This is made even simpler by incorporating aquaponics in the raft system because expensive hydroponic nutrient solutions and monitoring are not needed. Aquaponics is the combination of re-circulating aquaculture (fish farming) and hydroponics (growing plants without soil). The fish waste provides the nutrients the plants need and the plants, in taking up these nutrients, help to purify the water in which the fish live. This is an organic process with the only input to the system being fish food which creates a sustainable ecosystem where both plants and fish can thrive.
This aquaponics raft system is particularly successful for growing leafy crops like lettuce, herbs, chives, spinach, arugula etc. because of the high nitrogen content in the water. The raft system is ideal for these small plants that do not need a great deal of physical support. These leafy crops also do well with the lower phosphorous and potassium of the aquaponics system. The majority of hydroponic lettuces marketed commercially are bibb or European butter crunch types. This is often marketed as “Hydro-Bibb” lettuce. It is a good idea to start with these types and move on to other gourmet greens later. Generally you can start harvesting from 40-50 days after planting so it is best to plant each week to stagger your harvests. One of the best things about growing your lettuce inside with this method is that the average home temperatures below 78F are ideal for growing most lettuce year round.
What about the Fish?
Tilapia are generally the fish of choice for larger aquaponic systems because they are fast growing, can tolerate a wide variety of water quality conditions and have firm white meat. For small hobby systems, koi or gold fish work well. It is a good idea to also include a plecostomus cat fish to help keep the tank clean. Start with approximately one inch of fish for each gallon of water in the tank.
Materials for the System
Tank
Virtually any clean container that can hold ten or more gallons of water will work, but for esthetics and function, fish aquariums work best for most small systems. Fortunately, these are readily available used by looking in the Bird and Fish classified ad section of any major newspaper.
Under Gravel Filter and Pump(s)
These can be built, but it is easier to buy them and generally they come with used tanks. The filter needs a means of pulling water through the gravel to promote bio-filtration. This can either be done with an air pump and air stones, or with devices known as “Power Heads” that have an active water pump that draws water up the riser tubes of the filter. The best setup is to have the power heads for the filter and then supplement the dissolved oxygen in the tank with an air pump and air stones. Air hose tubing will be needed as well as a two way gang valve.
The Raft
For the raft we will use a sheet of Styrofoam about one inch thick that can be purchased at any hardware store and easily cut with a razor to fit the size needed.
Aquarium Gravel
Don’t skimp on this one. By buying aquarium gravel rather than using some other type of gravel you will be sure that it will not leach into your water and impact the pH. Buy enough to cover the under gravel filter with two inches of gravel.
Growing Medium
For this system, we only need a small amount of seed starting medium to get the plants started. This can be Rockwool, Oasis Cubes or Sure to Grow media. Some lettuce seed needs a cold period to help them germinate. After soaking your medium, add one or two seeds to each cube and place in the refrigerator for 48 hours.
pH Test Kit
This system is very easy to maintain, but starting with proper pH and maintaining it is the key to success. pH test kits are available for as low as five dollars and can be purchased at hardware and pool stores.
Siphon Cleaner
This inexpensive tool is available at all stores that sell aquariums and is indispensable for monthly tank maintenance.
Light Source
If the tank is placed near a sunny window external light may not be needed, but lights often come with used or new tanks and they can be used by changing the bulb to one appropriate for plants. This may not be adequate if the system is relying entirely on artificial light. Twenty to fifty watts per square foot is a good rule of thumb for grow lights if used exclusively. A small stand can easily be made of PCV pipe from which to hang the light fixture. Artificial light is generally provided to lettuce for 16 hours each day.
Setting up the System!
Tank Setup
The tank will be set up just like any aquarium. Place the under-gravel filter in the tank with the riser tubes installed, add gravel and then water. Connect air stones to tubing from the air pump and insert them in to the riser tubes from the filter or insert and plug in Power Heads. Once water has been added to the tank, the pH will need to be checked and adjusted as needed. If the system was just for raising fish it would be best to try to maintain the water at a pH of about 7.4. In combining fish culture with growing plants (aquaponics), the needs of both the plants and fish must be slightly compromised by maintaining a pH as of about 6.8. More often than not the pH of tap water needs to be lowered. Products for raising and lowering pH that are safe for both plants and fish are available at both hydroponics and fish stores and online retailers. If fish are to be added immediately, the water must be de-chlorinated, otherwise wait 48 hours before adding the fish. To start your system, add approximately one inch of fish for each gallon of water.
Raft Setup and Planting
The raft can be as large as you like as long as it can freely float on top of the water and allow room for feeding fish, filter tubes etc. If the tank is large it is better to cut several smaller sections of raft so they can easily be moved for tank maintenance. Starting 3 inches from the side, holes can be cut every 3 inches for planting tubes. Cut holes slightly smaller than ½ inch so that you will have a snug fit for the planting tubes then cut ½ inch PCV pipe sections of 4 inches each for each planting tube. Fill each planting tube by packing it snuggly with the chosen growing medium. The growing medium will serve to support the roots and to wick water up to the germinating seeds. Once seeds have been cooled for 48 hours they can be placed along with their medium cube, into the top of each tube. Next insert each tube into the raft with 2 inches of the tube below the raft protruding into the water. Depending on the type of fish in the system, they will trim any roots that grow out of the tube. Having a 4 inch tube allows space for sufficient roots to grow unmolested by the fish.
Maintenance
The good news is that this system is very easy to maintain. Each week, check the pH. If the pH is between 6.6 and 7.0 things are going well. If the pH is outside of this range it should be adjusted by using either pH Up or Down as needed. A pH of 6.8 is ideal. Fill the tank to top off the level with de-chlorinated water. Each month, use a siphon cleaner to vacuum the excess waste out of the gravel. Take the tank water level down ¼ with this process. Don’t throw this water down the drain; it will do wonders for indoor and outdoor plants. Fill the tank back up to the top with de-chlorinated water
This small system can not only be an attractive conversation piece, but it can provide enough salad greens and herbs for the whole family.
Dr. Christopher J. Kline is a master gardener and writer living in Paradise Valley Arizona. Chris can be reached at CKline72@Cox.net.
