Hydroponics

Dean said:

Anyone ever get involved in hydroponic? I'm interested in starting indoor growing of some fruits to have year round crops. I've seen some very nice hydroponic tomato plants but know nothing about it.

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Ok, what do you want to know? Basically, hydroponics is growing plants, no matter what type, by delivering a nutrient solution (fancy fertilizer) directly to the roots. Out of the last 6 years, we have grown hydroponically produced vegetables for 5 of them. The system is totally homemade and works very well.

Here's some pics:
http://img510.imageshack.us/img510/8193/1413nd5.jpg
http://img511.imageshack.us/img511/1970/0001558oi1.jpg
http://img510.imageshack.us/img510/8246/0001560yl5.jpg

You can build any size system you want. One that will hold just a few plants or one that will produce several hundred lbs of vegi's every couple weeks depending on the materials you can get ($$$).

The pictures are of my NFT type system. NFT stands for nutrient film technique and they are VERY easy to build. The main components are a nutrient reservoir, a pump (small semi-cheap pond pump) and troughs for the plants to sit in that are elevated at one end so the solution drains back into the tank.

You'll also need a meter if your tank is larger than a few gallons. My system is far more affordable than a factory made system and all parts are easily replaceable and found at hardware stores except the pump and tank. You also don't lose any water to ground run off or wicking of the surrounding soil. There's no weeding either and all soil born diseases are taken out of the equation.

I've tried three distinctly different types of hydroponics down through the years, and each has it's own pros and cons...

Floating tables, where your produce is literally floating on styrofoam sheets or wooden boards with holes drilled in them so the roots can reach the nutrient solution.
All you need for this is a tank about 3 or 4" deep, and a small agitator for the nutrient solution.

This works GREAT for low plants, like cabbage, head lettuce, stuff like that.
The really great part is that as you consume adult plants from one end of the water table, you can start seedlings at the other end and just push the growing boards forward to progress things.

Lots of commercial products are grown this way now since indoors they are not limited by the weather and you can grow crops in places where the soil pH isn't compatible with your crops.
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The next two ways are for taller or climbing crops.

Floating systems are impractical with tall growing or climbing crops since the 'Board' or 'Platform' would have to be very large to keep the crop from flipping it over (top heavy)
I have found it's much easier to grow the crops in PVC tubes or troughs and circulate the nutrient solution through them...
And then since the corn, tomatoes, climbing vines for peas, ect. can be suspended from the ceiling for support, with the PVC tubes or guttering troughs fixed, the plants get support.

The first way is pumping the nutrient through the tubes.
This means you will need to have the tubes un-level, with one end higher than the other so the nutrient solution can be pumped in one end, and gravity drain out the other.

You can use an elevated system, where the nutrient solution starts at the high spot in the system and flows to the bottom of the first tube (about 1" drop in 8' to 10'), then drains into the next tube which slopes the other direction to repeat the process.

One side of a saw horse can hold about 5 plants in 5 feet, and you can have about 4 runs of 5 foot tubes on one saw horse...
4 x 5 is 20 plants on one side of a saw horse, and there are two sides of a saw horse, so that's 40 plants per saw horse if you are growing corn...
A few less if you are growing tomatoes or bean plants since they spread out more than a corn plant does.

The second way is to gravity feed the plants on a table just above 5 gallon bucket level...
Lay out about 5 tubes dead level, and you might want to fill the tubes with pea gravel to help the roots disburse better.

All tubes are level with each other, and about 1/4" pitch to the low side at one end to the other so they drain SLOWLY.

Hook the bottom sides of all tubes to drain hoses, and secure them to a manifold.
Connect the manifold to the bottom of a 5 gallon (or larger) bucket.

When the bucket is lifted, the contents will flow into the root tubes.
When the bucket is lowered below the tubes, the liquid will drain back into the bucket.

Pea gravel will keep the roots from drying out, all nutrients are controlled from the solution you use, and feeding cycles can be very strictly controlled.

With nothing more than a pulley/rope and some counter weights, the bucket becomes pretty much weightless for you and doesn't require ANY outside power other than someone to lift it two or three times a day.

I prefer PVC tubing & pea gravel growing over open trough growing since many plant species have roots that are light sensitive.

Dean said:

The thing I've wondered about with hydroponics and growing eatable produce is the nutrients you use in the water to allow for growth. How safe are they?

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Just as safe as the chemical fertilizers they put on the ground save for the fact that these never enter your surroundings so they don't kill off mass amounts of beneficial bacterias in soil or cause nutrient salts to build up. Granted, if you had the land, there are more natural ways to do things that are good too. We have livestock and their waste is a very nice fertilizer but I can grow much more food in a much tighter spot with the hydroponics. In summer, I get 100 lbs of cucumbers and about 25 lbs of tomatoes from an area that's 16'x12' and I never have to worry about bugs. That eliminates any need for any type of pesticide or companion planting.

The main danger from chemical fertilizers (nutrient salts) in hydroponics is having an open loop system. In an open loop system, used nutrient is dumped via a drain pipe into the environment but in a closed loop system, it is sent back to the tank and reused until it needs filling again. Then, new water and nutrients are added but it's never dumped.

dilligaf said:

my thing with hydroponics is the price of nutrients as well as electric needed. Since this is a preparing site i need to remind folks that we are preparing so think ahead of what you may have to take into consideration in a worst case scenario. Do you have the ability to store any and all nutes and do you have a means to have power in any given situation we may face in the future..

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Nutrients can be stored in a five gallon bucket with an air tight lid. To combat cost, get them from a large company like southern agriculture. That's where I got mine. For less than $100, I got about 3 years worth of nutrients for my system using it 6-7 months out of the year.

For a situation where you had no power for prolonged periods, see post 8. Jeephammer's post, the part about lifting a bucket up and down to drain and fill a trough. That's called an Ebb & Flow system and you don't need electricity for it but you also can't produce as much food as other size systems unless you have many of the units built. It's fairly easy to build those too.

As it stands, if power went out for 2 days, my system would be ok, but any longer than that and the plants would die. I've never tried to bucket water into the troughs but that's what would happen if the power went out and didn't come back on... or the plants would be lost.

Just like JH said, there are pro's and con's for each system.

Blister, I didn't know the names for the different systems, I just had ideas and tried them out.
Ebb & Flow sounds about right!

I use solar pump now, when the comes up, the water flows, when it goes down, the water stops.
(old cordless drill motor, and PV solar panel was intended to charge batteries on a house boat that was totaled during a hurricane)

There are some VERY reasonably priced, high quality pumps out there, but I'm a consummate tinker, so I made my own...

Something I have learned, Fish Crap is the best natural fertilizer you can find!
There is a fish hatchery down the road from us, and they just throw out the fish crap from the tanks, but it works GREAT!

I also know that the small concentrations of chemical fertilizers we use, insect larva can live in the water, and although I personally have never tried it, people tell me even fish can live in the water tanks (if you aren't stupid with the chemicals!)

What I'd like to know...
Do you use pea gravel or anything for root holding?

Stuff like potatoes/carrots I know you have to use something to hold roots/tubers in place, but when I tried stuff like sweet corn, the pea gravel tubes seemed to do a lot better...

When doing lettuce, cabbage, ect, they seemed to like it without anything around the roots...

And I couldn't tell a difference with tomatoes, peppers, ect.
(Never tried cucumbers! Might do that next year!)

Blister's Photographs,







What kind of film are you using on the troughs?

JeepHammer said:

What kind of film are you using on the troughs?

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The troughs are covered in black polyethylene plastic. I stretch the plastic over the flat bottom and use hot glue underneath it to stick it down. Then I work my way up the sides and secure it underneath the outside bottom of the trough with duct tape. The gray kind, not the foil (real stuff). Most of the time a piece of good 2x4 about 4' long works well to help. After a season, I check the plastic. If the finished look of the plastic is fading I replace it. I don't want excess decomposition to contaminate the root system. I don't actually know if it will but I'm just playing it safe. To replace it, the easiest way is to cut through the old hot glue with a knife and recover it the same way.

It's the thick stuff, 6mil. Like you would put under a new concrete slab for a vapor barrier. It's cheaper to buy a large piece from a builder's supply store than a smaller piece from a retail store.

The white piece on the top is a piece of 24" wide polyethylene and it is to limit algae growth (keep sunlight out) and keep the trough cooler than it would be normally. The colder your nutrient solution is, the more oxygen it will hold. The tank is buried half in and half out of the ground and it keeps the solution nice and chilly. That top piece helps it stay that way.

Blister, I never used pots, except for trying to grow potatoes in 5 gallon buckets...
Just stuck the plants in PVC tubes with holes drilled in the sides and when I used a rooting material, I used washed pea gravel...

I had mixed results.

I used to tie the stems in place with old panty hose,
Flexible, and didn't damage the plant stalk or stem while the roots were spreading.
Once the roots take over, you don't need anything to hold the stems in place!
(you know that already! The root balls grow QUICK and THICK!)

Some plants just DEMAND something for the roots to get a grip on, Corn being one...
And you can't grow potatoes without a container full of something for the tubers to get started in...

How about some more pictures!
I'd be REAL interested in knowing how long per day you water and what your flow rates are!

Here is a tip for algae growing in your nutrient solution...
UV!
Trickle your nutrient water under, on or around a UV-C bulb and it will kill ALL living bacteria, algae, ect. in the solution!
Cheap, and it works GREAT!

I even use it to kill off pathogens in my drinking water from a well, and the water has always come back from testing with 'No Detectable Pathogens'.
It's virtually a 100% kill rate, and you can't get that from chemicals without harming the plants!

JeepHammer said:

Blister, I never used pots, except for trying to grow potatoes in 5 gallon buckets...
Just stuck the plants in PVC tubes with holes drilled in the sides and when I used a rooting material, I used washed pea gravel...

I had mixed results.

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I never did root crops or one-time producers like lettuce or cabbage. I purposely grew only vining plants that continually produced fruit to get more out of each dollar. The tomatoes (couldn't find those pics) were in 1gal pots filled with untreated cypress mulch as a medium. They were in a trough 3.5" deep and 24" wide. A .5" pvc pipe ran down the center with .25" tubing coming from it to feed each pot.

I used to tie the stems in place with old panty hose,
Flexible, and didn't damage the plant stalk or stem while the roots were spreading.
Once the roots take over, you don't need anything to hold the stems in place!
(you know that already! The root balls grow QUICK and THICK!)

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I use wires on the cantaloupe and tomatoes. Then, with the tomatoes, I tied nylon string loosely around the stem to keep it somewhere in the area of the wire and try and make them do one, gradual loop around the wire. The cantaloupe do well on the wire and just climb it by themselves. The cucumbers don't need anything. I just keep them at two stems only, 6" off the ground.

Some plants just DEMAND something for the roots to get a grip on, Corn being one...
And you can't grow potatoes without a container full of something for the tubers to get started in...

How about some more pictures!
I'd be REAL interested in knowing how long per day you water and what your flow rates are!

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The flow rate is around 1100gph from a 1400gph pump. It's magnetic drive so it's not that powerful and has to push water upwards which really isn't it's function but it takes very little current to run it. It runs 24hrs a day.

I have lost some pictures, like the ones of the tomatoes and a few others. I think they are either in another computer or on a disk somewhere. I could go out and take a few now but all we would see is what happens to a greenhouse when it's not maintained for a year. lol. It looks pretty crappy right now. There are weeds 4 or 5ft tall and the last season I grew plants in the system, at the end of the season, I just walked out and unplugged it and left. All those dead plants are still there. It looks pretty rough.

Here is a tip for algae growing in your nutrient solution...
UV!
Trickle your nutrient water under, on or around a UV-C bulb and it will kill ALL living bacteria, algae, ect. in the solution!
Cheap, and it works GREAT!

I even use it to kill off pathogens in my drinking water from a well, and the water has always come back from testing with 'No Detectable Pathogens'.
It's virtually a 100% kill rate, and you can't get that from chemicals without harming the plants!

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Since it gets so hot here, the plastic is necessary to keep the solution and root zones cool. The light is a pretty good (very good actually)idea but the plastic fills several needs at once and I still have a couple hundred feet of it left.

I wont dump any chemicals in there. Before I bought the plastic, I use to clean the algae out by hand. lol

First post

Hi everybody, for those of you who are concerned with too much dependance on manufactured chemical fertilizers, there is a natural, organic, and (insert half a dozen other hippy-dippy adjectives here), way to grow your food hydroponically, with minimal electricity. A few posts back Blister mentioned a technique called aquaponics. This technique combines hydroponics (growing plants in a soilless medium) with aquaculture (raising fish). The plants and the fish live in symbiosis with a bacteria (which occurs naturally where there are fish and plants) to recycle fish waste into plantfood, with the plants providing a natural filter to clean the fish water. I have not tried this technique yet, but there are a couple good videos and websites around if you are inclined to look. I have read that this technique uses 70% less water would be used to grow vegetables in a more traditional way, and a 95% reduction of water usage from traditional aquaculture techniques! As for electricity, all you would need is a pump suitable for whatever size unit you decide to build which needs to run 24/7, which can easily be powered by a small solar cell/battery array. Even better would be to have a small steam powered pump. All the rest of the functions (aeration, timing the watering cycle, flushing and draining) can all be provided by simple mechanical means. If you are looking for a place to start, look up the article on "barrelponics".