Hydroponic Systems Blog

Grow Cubes are a great invention for the hydroponic gardener. They are small cubes in which you germinate a seed and then transplant the entire cube with seedling directly into a hydroponics system. I use 2 brands; Jiffy-7 and Grodan. Jiffy-7's are small round, compressed discs of mainly peat moss wrapped in a plastic mesh. When the cube is watered it expands (you loosen the mesh) and you place a seed into the center for germination. Grodan cubes are made of compressed rockwool pressed into sheets. A seed is pressed into a ready-made hole in the center of the cube for germination.

Cubes can be placed directly into hydroponic systems for germination or they can be used 'stand-alone' for germination and later transplanted to a hydroponics garden. So there is no more need of separate flower pots or trays for germination - just use a cube and place cube and seedling directly into any kind of hydroponics system. Rockwool is marketed mainly for NFT and drip while Jiffy-7's seem to work best with systems using growing medium.

I have had mainly a good experience with both types of grow cubes but prefer Jiffy-7s at the moment. Grodan cubes seem to have a super water retention ability which caused many of my seedlings to die of 'damping-off' disease. This was not Grodan's fault, it was mine - I have always had a tendency to overwater... whereas Jiffy-7's seem to fit very well into how I germinate and water. I would heartily recommend both brands so if you have not tried them out yet, you are missing out!

October 2, 2006 21:05 - Participate in a seed exchange...

When I was planning my hydroponics garden this year I knew exactly the variety of tomato I wanted... beefsteak; a rather large meaty variety I had when I was a child. The problem was that no nursery in my local area had any, and those that did only had some scrawny, sickly plants left. I could have scoured some seed catalogs and spent some money instead I gathered the few 'big boy' tomato seeds I had and found someone at work willing to trade me some beefsteak tomato seeds for the 'big boys'. This is the basis of a seed exchange... only imagine doing it via a website and across a country.

Let's say you have read about some old and obscure tomato variety called, 'big rainbow'. You post a message and offer to trade seeds you have for some 'big rainbows'. Maybe you're looking for Black Spanish radishes or Red Rubine basil, Lobjoints lettuce or Tangerine Gem marigolds and have no idea where to find them. You can be sure of one thing; someone out there has the seeds and would probably be willing to trade for them - all you have to do is find a seed exchange (Google search) and post a message.

You can even trade plant cuttings through a seed exchange. The possibilities here are endless. Just be careful of international restrictions for seeds and plants sent from country to country. And if there is any interest I would be willing to host a seed exchange on this website...

October 3, 2006 15:56 - Heritage and Heirloom vegetables; what are they?

The terms 'heritage' and 'heirloom', when applied to vegetables, can be used interchangeably. These terms describe vegetables being grown before large scale modern agriculture was implemented. They do not work successfully with modern agricultural techniques so are just not grown anymore.

Did you know that a study was conducted comparing vegetables in market 100 years ago with those being sold now? And they determined that over 96% of the variety from 100 years ago is now gone - many are extinct. This is all due to modern farming techniques...if a tomato, for example, yields well and is a deep red color with a thick skin to protect against harvesting and transportation, why not breed more of these because they travel well and are easy to sell? It's too bad taste was bred out of them also. But they sure look pretty for the consumer...

Some of these heritage varieties have survived through the efforts of individuals patiently growing, saving and distributing seeds to others. These vegetables may not look as pretty as current marketed types but they have unique textures, colors and flavors and are well worth growing for yourself. Seeds can be bought or traded for on several seed exchange and garden websites - and we are not just talking 'tomatoes'. Heritage varieties include many vegetables including lettuce, radishes, rhubarb, asparagus, corn, beans, squash, peas, just to mention a few. And I don't need to mention that heritage varieties would grow extremely well in a hydroponics system.

October 4, 2006 19:23 - The popular tomato...

This is about the popular tomato, one of my favorite vegetables. Officially it is classified as a fruit but tastes more like a vegetable to me. One hundred years ago tomatoes were from open-pollinated plants that bred true - these are now called heritage or heirloom varieties. Now there are 2 more categories of tomatoes; GMO and commercially grown hybrids.

GMO vegetables or 'Genetically Modified Organisms' are plants who have had their DNA tampered with. For instance, to make a tomato that is more frost resistant you may splice some cold water fish genes into it's DNA (actually, something like this has really been done). The problem is that even though we have mapped entire genetic structures we really have no idea what specific genes do...they act differently in different locations and can be triggered or changed from environmental stress or by the presence of other genes. So spicing genes from one organism to another is really just a 'crap shoot'.

The third category, commercially grown hybrids, are tomatoes cross-bred and selected over many generations to look nice and travel well and, as a by-product, to taste bland.

Within these 3 categories are distinct sub-categories of tomatoes; determinate, indeterminate and semi-determinate. Determinate types are those that flower and produce tomatoes then stop producing and die. They tend to be smaller, bushy plants. Indeterminates are those that produce and keep on producing until the plant is killed - usually by frost. Most modern commercially grown varieties are indeterminates and tend to grow into taller, vine-type plants that need to be staked up or they will fall over. Semi-determinates produce smaller and smaller yields after the first yield and are not as tall as indeterminates.

Each of the 3 main categories contain determinate, indeterminate and semi-determinate tomatoes. So when you are searching for seeds or tomato plants for your hydroponics garden you need to be aware of just what you are getting...

October 5, 2006 09:06 - On-site gardening videos are here

This is a supplemental blog entry to advertise the addition of new video clips on this website. They will cover general gardening and hydroponic topics and are instantly viewable for free.

Periodically I will change the video selections so stay tuned... To view the videos, click here.

October 5, 2006 14:36 - Carbon dioxide and it's importance to your plants

Carbon dioxide or CO2 is essential for a healthy plant. Click here for some basic plant biology. As you can see, CO2 is an essential building block in glucose production which is used as energy for new plant growth. It is normally present in the atmoshere at 3 PPM (parts per million) and if it falls below this quantity, plant growth will slow down and eventually stop. Higher quantities of CO2 will cause a plant to grow more and faster.

Is this something to be concerned about? If your hydroponics garden is outdoors and receives an adequate flow of fresh air, you have nothing to worry about. If your setup is indoors or in an enclosed greenhouse you may need to introduce some CO2 into your garden. So how would you do this?

The easiest way to add fresh CO2 to your garden is to merely spend time with your plants. We exhale a lot of CO2 in a short period of time which is probably one of the reasons why plants that receive a lot of attention flourish. A second way would be to put some dry ice on a plate near your plants to melt - this also produces CO2. The third way would be to get a cannister of CO2 and release it periodically in your garden.

Whichever method you use, keep in mind that CO2 is heavier than air so will sink to the floor and do nothing for your plants without some kind of ventilation fan. 'What do I do?', you may ask. I keep it in mind but never worry about it even though my plants are in an enclosed greenhouse. I have put some windows in the structure and sometimes I will turn on a floor fan for circulation, mainly to bring the temperature down and I have not had a problem.

October 6, 2006 14:29 - All about 'Earthjuice'

'Earthjuice' is the generic name for a variety of liquid fertilzers, all produced organically from natural ingredients. There is an earthjuice fertilizer for shrubs, lawns, trees, flowers and vegetables. In my opinion it is definitely a superior product with no competition even coming close to delivering the quality that earthjuice delivers.

So, what's in it? 'Earthjuice Grow', which promotes a vigorous leafy growth has an NPK of 2-1-1 and contains bat guano, feather meal, blood meal, steamed bone meal, Norwegian sea kelp and oat bran - all the nutrients a growing plant needs. After my previous blog entries on seaweed and guano I am very impressed with this product...Used in any kind of hydroponic system, organic or not, this fertilizer is unbeatable!

As an unrelated item: this website is now published! Check out our article entitled, 'Consider a Hydroponic Garden as a Supplemental Growing Method' in the Nov/Dec issue of Countryside magazine!

October 7, 2006 18:36 - The versatility of the Mittleider Grow box

Remember the Mitleider Grow Box? If you don't, click here. It is a basic board box with no top or bottom and what makes it so versatile is its use as a hydroponics system and the fact that it can be set anywhere at all outside. I would pick a place where a garden normally could not grow like on a gravel surface, a rooftop if you live in a city, a terrace or even on a rocky surface.

Such a garden will successfully grow tomatoes or any plant of your choice and it will grow faster and yield more than a normal dirt garden plant. It is successful because it becomes a type of hydroponics system so plant roots do not need to grow large because they constantly receive all the nutrients needed.

To set this up, build a box, choose a location and set it down. Fill the box with a mixture of 1/2 sand, 1/4 vermiculite and 1/4 perlite. Finally, plant your seedlings. Water them with a mixture consisting of 1.5 teaspoon fish emulsion, 1.5 teaspoons liquid seaweed extract and 1 tablespoon bloodmeal - these measurements are for 1 gallon. And that is it...

This method was successfully implemented on an inner city rooftop in Montreal so you will have no trouble. The light density growing medium is enough to anchor a large plant and aerated enough to get needed nutrient to the entire plant root system. The aerated medium also encourages a good growth of bacteria to further benefit the plants. Just make sure to flush the system with plain water every 2 weeks to keep the bacterial levels down or your plants will suffer from 'too much of a good thing' grabbing needed oxygen. Of course if you live in an area receiving a lot of rain, you will not need to flush the system yourself.

October 8, 2006 12:05 - How close together can you place your plants?

There is established recommended spacing for each type of plant when transplanting into a dirt garden. This allows room for the plant to spread out it's foliage and to expand it's root system in search of needed nutrients. In a hydroponics garden, the constant dose of nutrient solution into an aerated medium will result in a smaller root system allowing the plant to redirect it's energies into growth. Therefore you can plants closer together than recommended. But how close is close enough?

Too close will increase the risk of pest infestation and disease and too far away is merely wasted space. Another factor to keep in mind are individual plant characteristics; for instance, tomatoes need room to spread out or strange things will happen. In my first hydroponics garden I planted 6 beefsteak tomatoes in a Mittleider Grow Box, 3 feet by 6 feet. This was too many plants and way too close...

Even though each plant received an adequate dose of nutrients, the lack of room to spread out made them grow very tall in their effort to spread out. I ended up with 14 foot plants on top of a dense tomato plant jungle I could barely see into to pick tomatoes. Just as they achieved full tomato production they caught a plant disease and all died despite all my treatments.

In the 3 foot by 6 foot grow box, two tomato plants would have been sufficient - not six...So when deciding how close to put your plants, stick with the recommended distance and decrease the distance by 1/3 so if 3 feet apart is recommended, space them 2 to 2.5 feet apart at the closest. Just use your best judgement. If the plants tend to spread out then plant the recommended distance apart or you will be searching through a jungle of foliage to find your vegetables.

October 9, 2006 16:30 - Supplemental Hydroponics Equipment

Hydroponics supply shops offer a a huge range of supplemental items for your garden. There are available separate nutrient mixes targeted to the budding phase of vegetables, the growing phase, for flowers, broadleaf plants or propagation including a vast number of organic nutrients. And let's not forget about growth supplements for rooting, budding or leaf growth.

For propagation you can buy mats, thermostats, sprayers, water warmers, stake labels, tray inserts and propagation domes. Also available are cloning gels and rooting powders. And you can get trays, pots, tubing, fittings, growing cubes, all kinds of growing medium and a huge selection of pumps, both submersible and dry.

For those with indoor systems there are flourescent light systems and metal halide, moveable light rail systems and reflectors. You can buy CO2 measuring devices, CO2 cartridges, monitors and fuzzy-logic controllers. Next are the fan systems, pest control larvae, PH test equipment, humidity indicators and scales.

Does this list make you as dizzy as it does me? Personally I try to avoid any kind of shopping and I try to keep my hydroponics systems simple and easily manageable. I'm not saying these products are of no use, only that they are not something I would generally need. But if you like shopping you may benefit from some of these supplemental products. Just browse the website of any online hydroponics store to see what is available...

October 10, 2006 10:24 - Rate this site...

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October 11, 2006 14:25 - Have an indoor garden? You may need to manually pollinate your plants

In order to form vegetables your plants need pollination to occur. Outside, in the open, this is generally not a problem but indoors or in an enclosed structure you may be forced to manually intervene in order to get vegetables.

Let's start with types of pollination. There are 4 types of plant pollination: plants needing pollen from different plants, plants that pollinate themselves, plants that can self-pollinate and receive pollen from other plants through wind and insects and, finally, those with male and female plants or flowers. Pole beans, tomatoes and certain varieties of peas are some examples of plants that will pollinate themselves, while most will need wind or insects meaning manual intervention.

An indoor garden will not generally get wind or pollinating insects so you will need to do some manual pollination. I buy packages of inexpensive, small paint brushes used by children. These are perfect for lightly rubbing the flowers to get pollen and transferring it to another flower to pollinate. This method does work especially when combined with lightly shaking the plants and turning a fan on them now and then.

For plants with male and female plants or flowers like some cucumbers and squash, read how to identify the male flowers or plants and use the 'paintbrush' technique on them as well. Even self-pollinators like tomatoes will benefit from a light shaking or a fan blowing on them.

October 12, 2006 15:51 - Build a container garden for the winter

Right now where I live, leaves are turning orange and are starting to fall. Yes, fall and then winter are right around the corner. This year's greenhouse and hydroponic gardens have been disassembled and stored away until spring. I am not planning on building an indoor system yet, at least not for another month. But I will make a container garden or two.

These are very simple and very easy to maintain. My favorite setup is a small neck vase filled with nutrient solution and plugged with a wad of cotton in the neck through which I insert one plant allowing it's roots to dangle in the nutrient solution. I also place an aquarium bubbler air stone in the solution attached to the small aquarium bubbler motor to supply oxygen. Place this near a window and you are all set!

Mainly I grow basil or parsely in these setups and use the leaves when I need them but you could really grow any small plant. Another type of container hydroponic garden can be in a small plastic tub. Fill it with nutrient solution, add the aquarium air bubbler and put near a window. Lettuce can be grow in such systems by floating them on pieces of styrofoam or small wood floats. Changing the nutrient solution every two weeks is virtually all the maintenance required...

October 14, 2006 21:20 - Indoor hydroponic garden lighting

Growing plants indoors will most likely require some kind of lighting system. For this you basically have 3 choices, high intensity lights (HID) of either metal halide or sodium vapor and flourescents (don't even think about incandescent lighting). HID lighting systems provide enough intensity to grow healthy plants but are very expensive to operate. Due to their design they also require a ballast to work. Click here for more information. They are 'hands down' the best lighting you could use, that is, if you can afford to buy and operate them.

That leaves flourescents. They are cheap and relatively inexpensive when compared to the cost of HID's and they come in bulbs which emit different wavelengths for different plant growing stages. Sounds perfect, doesn't it? Their one drawback is that light intensity decreases extremely fast as you move away from the bulb so they should be placed just inches from the tops of your plants. They also discharge light intensity straight down so a few inches off center will show a drastic decrease in intensity.

But, I personally feel they are the best option available at this time. To compensate for the decreased intensity at different spots in the garden you can place reflectors around your plants made of aluminum to 'beef up' the intensity and the lights can be placed on automated movable tracks to more evenly distribute light discharge through your garden.

October 15, 2006 19:44 - An NFT system with flexible hose?

This morning I was walking through our local 'Home Depot' which is the latest mega-store addition to our area. Aisles upon aisles of lumber, lights, nails and hosing. It was the hose that caught my eye - all I could picture was an NFT system constructed from that hose. Just imagine, you could bend it to flow around a room or greenhouse and reposition it whenever you want even with plants growing in it.

The hose was the right size, about 1.5 to 2 inches in diameter, and there was quite a variety to choose from although the most common was collapsible ducting material. I just might try an experimental NFT system out of this material. It would be easy to drill through and manipulate - although devising something to plug the ends through which you could snake through input and drainage hoses might be a bit challenging. I'm going to think about this and if anyone out there has done something similar or has some further ideas, let me know.

October 16, 2006 22:16 - Build your own Chinampa

Anthropologists have found evidence the Aztecs built a type of hydroponics system called a Chinampa, or floating raft. These were rafts made of rushes and reeds lashed together and topped with nutrient rich soil from the bottom of Lake Tenochtitlan. Crops were planted in the soil on the raft and roots extended down into the lake.

I have read arguments that this is not hydroponics because it involves dirt - well, it does and it doesn't. The dirt and reeds were used for plant anchoring purposes with nutrients coming in from the roots dangling into the lake. The beauty of this system is the fact that nutrients were leached from the raft dirt onto the roots in the water to feed the plants.

Whether this is 'true' hydroponics or not does not really matter for it is still basically gardening without soil. What I would like to see is a modern version of this system. I have in mind a small wood frame box raft covered with a mesh or net. On top of this is placed some hay covered with a thick layer of dirt sprinkled with hydroponic nutrient. Plant your vegetables on this and normal wave action on the raft bottom would start leaching some nutrients down to the roots. Of course, whenever it rains a new layer of dirt would need to be added to the top of the raft...

October 17, 2006 19:22 - Building the perfect compost pile

Compost piles can provide an excellant supplemental source of nutrients for your garden. If you have an organic hydroponics garden then a good compost pile is essential for healthy plants. And as with most projects, there is a 'right' way and, in this case, a 'not so right' way to build a compost pile. But first, let's talk about methods and compost ingredients.

There are two methods of composting; cold composting and hot composting. The 'cold' method is a compost pile left to it's own with no management. Scraps are merely thrown into the pile and never mixed or watered. This method will produce compost after an extremely long time and tends to be rather smelly. This is the 'not so right' way. The second method, or 'hot' composting, is the preferred way to create usable compost in approximately 6 weeks.

Hot composting involves periodic watering of your 'pile' and frequent (twice a week) mixing of the pile with a pitchfork. This encourages bacterial growth to break down the organics and leave plant nutrients as a by-product.

So what can you put in your compost pile? Try to maintain a ratio of 25 'browns to 1 'green'. 'Browns' are carbon-rich organic materials such as leaves, hay, sawdust, rice or even shredded newspaper and 'greens' are nitrogen-rich materials such as lettuce, tea bags, coffee, egg shells and other kitchen scraps. The goal is to provide the right environment for bacterial colonies to break down the organics - they use 'browns' for energy and 'greens' for protein. The closer you are to the mix ratio, the faster you will get compost.

As an added benefit, compost piles attract worms and worms excrete 'castings'. Worm castings are an excellant source of nitrogen for your plants - it is so good, in fact, you can actually buy worm castings. And, in case you did not know, worms absolutely love old coffee grounds...Good luck and happy composting!

October 18, 2006 19:13 - Using tap water for hydroponics? Is it safe?

Living in a rural setting I am fortunate to have a drilled well for my drinking water. It is 280 feet deep so my water is filtered by the ground and is clean and pure. Every few years I get it tested for e. coli bacteria just to be safe. Most people, however, live in suburbs or city where supplied water is treated for bacteria. I am referring to the United States although this blog entry is probably applicable to most parts of the world.

Treated water is water infused with chlorine or some derivative to destroy bacteria and keep it safe to drink, or potable. The problem is, 'is this water good for your hydroponics garden?'. Treated water in the United States is infused in one of three ways: good old-fashioned chlorine, chlorimine or chlorine dioxide, whose sole purpose is to kill bacteria and fungi which may make you sick.

Chlorine has been around for decades. It adds a distinctive aroma to water and effectively kills all bacteria but it's one drawback is it's instability, meaning it dissipates within a day or so. To get around this, water treatment centers are starting to use chlorimine instead of chlorine. Chlorimine is a mixture of chlorine and ammonia which will never dissipate but it is not very good at killing bacteria so a higher level is used. The last way is chlorine dioxide which is a gas that is infused with water to create chlorite which also does not dissipate. You really should find out which type of chlorine treatment is in your water so you can deal with it.

In terms of hydroponics, chlorinated water will kill all bacteria around your plants including the benefical kind but will dissipate in 24 hours so this water can be introduced to plants every 2 weeks when you change nutrient water to keep bacterial levels down and will soon dissipate. Bacterial levels will soon rise, so not a problem. Water treated with chlorimine or chlorine dioxide can be a problem. The water will not hurt the plants but do you really want to introduce these chemicals and their residue into your hydroponics system? Not me. Fortunately there are neutralizing chemicals available to get rid of this stuff.

If you find that your tap water is infused with chlorimine, choose your neutralizing chemicals carefully or you may end up neutralizing the chloine and leaving the ammonia - not something you want...

October 19, 2006 19:56 - Tomato trivia and history

The common tomato has had an interesting history. It is one of the few non-poisonous members of the nightshade family along with potatoes and eggplant and is really a fruit rather than vegetable making it a rather large berry.

The tomato is believed to have originated in Peru based on the theory that the part of the world with most tomato relatives and similar genetic offshoots is probably where it came from. It is thought to have migrated to Central America through trade over the course of thousands of years where it was first discovered by 16th century European explorers in the hands of the Aztecs.

In fact, the word 'tomato' came from the Nahuatl Aztec word, 'tomatl'. Soon after it was brought back to Spain it became a kitchen staple throughout Southern Europe but was not easily accepted into Germany or England. The Germans felt that it resembled the 'wolf peach', another member of the nightshade family believed to be used by witches to create werwolves and the English thought it to be poisonous.

In fact, the leaves of a tomato plant are poisonous but this idea was more likely due to accumulated lead poisoning from the dishes the rich ate from that somehow became associated with tomatoes. The poor never seemed to have a problem with the tomato but they ate from wooden dishware.

This belief of the poisonous qualities of the tomato persisted so the tomato was never really eaten by early American colonists. In fact there is an uncoroborated account of a person attempting to commit suicide by eating a bushel of tomatoes in front of the Boston courthouse in 1820. It attracted a rather large crowd of on-lookers who were rather surprised that the poor soul did not die...

In any event, the tomato has come a long, long way and is one of my favorite vegetables.

October 20, 2006 21:39 - Logee's Greenhouse in Danielson, Connecticut, USA

Today I would like to talk about Logee's in Danielson, Connecticut. It is a complex of interlinked greenhouses containing thousands of plants, shrubs and trees. They specialize in orchids and tropical plants of all kinds - and the best part is they are open all year round. During the winter months when snow starts to become very tiring there is nothing like a trip to Logee's to help you remember the warmth, smells and colors of spring and summer...

Logees also has a thriving mail-order business - check them out by clicking here. How do I know all this? I grew up with the owner, Byron and his brother Jeff, and spent many a summer playing around the greenhouses. They have been open continuously since 1892. This is not a typo - they have been in business in the same location for 114 years...

Take a trip there and you will not regret it. Check out Byron's tropical fruit trees and ask about his grafting experiments while sitting on the small park bench in the middle of a dense greenhouse jungle. Look at hundreds of orchids and banana trees. The place is truly a wonder!

And I guess I should mention that I refer you to them freely. I am not an affiliate of theirs and receive no compensation of any kind if you visit or buy something from them.

October 22, 2006 14:58 - The difference between 'organic' and 'hydroponics'

I was just speaking with a friend of mine and the subject of this website came up. He asked a question that many people take for granted. Since he knew my website concerns hydroponics, he asked if there were many people interested in this type of organic gardening. Somehow, 'hydroponics' has come to mean 'organic' to many people even though they are two completely different topics.

I explained that 'organic gardening' is a method of growing vegetables using materials that have not been processed and changed from their original natural state into something chemically produced and that 'hydroponics' was a type of gardening involving no soil and nutrients mixed with water. As a method, organic gardening can be practiced with hydroponics or with conventional dirt gardening. Therefore, hydroponics systems using chemically produced nutrient fertilizer is still hydroponic gardening but not organic.

So organic hydroponics is not really which hydroponic system you use it concerns the use of organic nutrients and organic pest and disease control. Organic hydroponics relies on the development of a thriving bacterial colony around the plant root system to help regulate plant processes and to impart increased plant disease resistance. Organic nutrients help build and replenish these bacterial colonies.

And don't forget that a complete flushing of the organic system is needed every 2 weeks to a month to cut down these ever-expanding colonies or your plants may smother (bacterial growth eats up oxygen so too much bacteria can literally take all available oxygen away from plant roots).

These thriving bacterial colonies should be a mixture of anerobic and aerobic type bacteria. Anerobic bacteria thrives in places with little to no oxygen and can give rise to some unpleasant organisms. Aerobic bacteria needs oxygen and this is the bacteria beneficial to your plant. As aerobic bacteria multiply, oxygen is consumed which causes a decrease in aerobic bacteria and an increase in the 'not so desirable' anerobic bacteria. To keep up these high levels of aerobic bacteria is another reason to flush your system periodically with plain water. The flushing will wash away most of the bacterial colonies and suck oxygen down to the plant roots allowing aerobic bacteria to thrive.

I hope this small discussion has cleared up some misconceptions...

October 23, 2006 19:24 - The difference between a water garden and a hydroponics garden

Everywhere I look, the paper, TV ads, billboards, I see advertisements for water gardens. So what is a water garden and is this the same as hydroponics? A water garden seems to be a small pool with some natural landscaping features added. These are filled with 'koi', a goldfish relative and various aquatic pond and bog plants such as water lettuce, water hyacinth and water lillies to name just a few. Line the pool with a pool-liner and add in a submersible water pump to provide some kind of small waterfall and you have a backyard pool or water garden.

In theory, such gardens are supposed to be complete ecological systems in that the water is oxygenated by the waterfall helping the aquatic plants to grow, the koi and other scavengers will clean the pool of algae and a good source of sunlight will keep the plants growing. Such a garden will also soon attract frogs and, I hate to say it, racoons.

Is this hydroponics? In theory, yes, because the plants do not grow in soil and obtain all nutrients from the water. Except...the plants are aquatic plants adapted by many years of natural selection to live in the water. Therefore it is not really hydroponics as I see it. These gardens are merely for decoration and not food production.

I suppose you could float some low-growing vegetables such as lettuce in the pond to grow but you would need to add nutrient to make it work. Water gardens are nice to have but it is definitely not hydroponics...

October 24, 2006 21:48 - Types of beneficial plant microorganisms

In previous entries I talked quite a bit about bacteria and fungi and the proper balance needed between the aerobic and anerobic microorganisms in your hydroponic growing medium. The beneficial bacteria and fungi in your plant root systems perform 1 of 3 possible functions: they free up soil nutrients for plant use by the breakdown of organic matter, they can enter a symbiotic relationship in the root systems meaning that the microorganism as well as the plant benefit from one another and, lastly, they can help suppress plant disease.

Symbiotic microorganisms include Rhizobia, a nitrogen-fixing bacteria, that attach symbiotically to plant roots and convert nitrogen in the air to proteins that plants use and mycorrhizal fungi that help conduct water and nutrients through plant roots.

Bacteria such as Bacillus Cereus, Circulans and Paeniticillus Polymxa help suppress plant pathogens or disease. You can see that such microorganisms are very important in growing healthy plants so be aware they are there and needed, and do not get rid of them needlessly out of some preconceived notion that 'the only good bacteria is dead bacteria'.

October 27, 2006 19:24 - Cleaning your hydroponics equipment

Every 2 weeks I flush and drain my hydroponics systems, scrub the nutrient solution container and hoses and replace the nutrient solution. This is to keep bacteria and algae in check, flush out accumulated mineral salts from the system and replace needed nutrients. I used to use microchlor which is an industrial sanitizer that supposedly flushes out completely when rinsed with water. In American grocery stores in the produce department, microchlor is in the water that is sprayed onto vegetables to keep bacteria from growing - which is a good reason to wash all vegetables before eating.

I wasn't feeling too comfortable about this product so I switched to small amounts of bleach as a sanitizer during cleaning. The chlorine will kill all bacteria and washes completely out to a few parts per million if you rinse at least 5 to 7 times with water. After a while I did not want to introduce any outside chemicals into my hydroponics system so I stopped using bleach as well.

Now I use a vinegar and baking soda mixture which cleans and sanitizes just as effectively as the harsh chemicals but is safe to ingest. And I have to admit that these 2 ingredients seem to 'work miracles'. What I do is wipe out the nutrient container with a damp towel, add 2 cups or so of white vinegar and swish it around. Vinegar, or acetic acid, is a great cleanser by itself.

Next I add maybe a half cup of baking soda into the vinegar, watch it foam up and then easily scrub out all accumulated slime. When baking soda, or sodium bicarbonate, is added to vinegar the addition of an alkaline to an acid causes an 'acid base reaction' and the release of carbon dioxide in the foaming process. The mixture turns to carbonic acid and breaks down to CO2 and water.

As it turns from acid to CO2 and water, fatty acids are broken down into glycerine which can be easily removed making this mixture a very powerful cleanser and sanitizer. Give it a try. Also keep in mind that this is a general all purpose, 'around the house' cleaning formula as well.

October 28, 2006 12:11 - A foolproof indication that it is time to flush your system

A good balance of bacteria and fungi in your plant root system will impart to your plants increased disease resistance and more efficient regulation of plant processes. But these benefits come with a price...as microorganisms multiply, more oxygen is taken from plant roots so if allowed to multiply indefinitely, bacteria and fungi will eventually smother your plants. Therefore a good system flushing with plain water every 2 weeks is essential for a healthy hydroponics growing system.

What are some signs that it is time to flush the system? If growing medium is not loose enough and aerated, plants may become oxygen starved and wilt or they may be showing toxic effects to a build-up of too much mineral salts in your growing medium. The best indication that you need to flush the system is the presence of mushrooms at the base of your plants.

One of the beneficial fungi mentioned are mycorrhizal fungi that attach to plant roots in a symbiotic relationship and mushrooms are merely huge colonies of this fungi. This means that the presence of a mushroom indicates a very large presence of fungi requiring a lot of oxygen so it is time to pluck the mushroom and flush the system. It is just an indication, not a time to panic...

October 29, 2006 17:43 - Hydroponics at work in the Negev Desert

The Negev Desert covers 50 to 75% of Israel and contains only 10% of the population. It is what you would expect from a desert - hot, dry and poor farming soil. Yet the Israelis have developed an ingeneous method of food and vegetable production in this uninhabitable place by using a mixture of aquaponics and drip hydroponics on fish farms to hydroponically grow vegetables.

They raise Tilapia fish on fish farms that are harvested and brought to market when they reach a certain size. Tilapia is a cichlid species of fish and is fast becoming a favorite the world over. I have not eaten one yet it is the fifth most consumed fish in the United States. They are easy to grow because they survive shock extremely well, subsist on a less expensive cereal based diet and can live in brackish water. So where does hydroponics come in? Let's look at the process...

To start, deep wells are dug to obtain brackish underground fresh water and pumped into pools in which Tilapia are grown. Waste pool water is saved, passed through filters and then fed to hydroponic plants through a drip system. This system has been in effect for over 30 years and has proven extremely successful. So successful, in fact, that plans are being developed to build desalinization plants so underground salt water can also be used.

This is a very good example of aquaponics at work. Aquaponics will not work well in small systems such as aquariums with aquarium type fish because thay cannot live in brackish water causing aquariums to be cleaned regularly which would eliminate all fish waste with its associated plant nutrients. But if dirty aquarium water was saved, aged and filtered it would be a good organic plant food for any hydroponics system.

October 30, 2006 15:20 - What is pH?

pH is an acronym for 'potential from hydrogen' relating to the activity of hydrogen ions in a solution which determines how acidic or how alkaline (base) a solution is. Phew! I'm not a chemist so the preceding sentence does not quite make a whole lot of sense to me but it does explain what 'pH' is. We are concerned with pH because nutrient water that we feed our hydroponics plants with must be within a certain pH range or the plants will not survive.

pH is based on a scale of 0 to 14 where 0 is corrosive acidic, 14 is corrosive base and 7 is neutral. Plants generally like a slightly acidic pH somewhere from 6 to 7 on the scale. If your nutrient solution falls out of this range, your plants will begin to suffer. The 0 to 14 scale is logarithmic meaning that a pH reading of 8 is a tenfold increase in alkalinity from a reading of 7 so a slight change in pH is very important to note.

I do not really worry about pH levels because I had my water tested and it is neutral with a pH of 7 and since I replace nutrient solution every 2 weeks I have no pH related problems. You see, the pH of your nutrient solution may start at 7 and then over time, with evaporation of the solution and constantly running it through growing medium, the pH will change and it will change drastically. So it is vital you replace nutrient solution periodically!