Growing Food in a Box of Water

Lilou

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While looking for ways to generate income on our farm, we’ve come across what is called the “Kratky Method” of hydroponics. It is described as a “set it and forget it” method. It does not require any electricity or flow of water and aside from the initial “planting”, there is minimal labor involved. The amount of water needed from seedling to maturity is vastly reduced when compared to the amount needed if the plant were in the ground. A head of lettuce will need 15-20 liters using the Kratky Method, in the ground, a head requires around 250 liters! So this method is superb for areas with water shortage or just to save on labor.

The secret is the placement of the plant roots in the hydroponic water solution. This can be achieved a couple of different ways – one, is to purchase what is known as net cups (available from Amazon) the second, which is what we used, is to cut 6mm holes into a plastic drinking cup (sides and bottom). The cup holds the seedling and allows only the tail of the roots to be submerged in water, while leaving an inch or so of the root exposed to the air. This exposed root provides the needed oxygen for the plant without circulating water.

The NPK (nitrogen, phosphorus, potassium) ratio is specific for each type of plant and can easily be found online in a search. Micronutrients are also included in the mix to mimic what is found in soil -Boron, Copper, Manganese, Zinc, Molybdenum, and chlorine – this is called the Master Blend. In addition, the ph of the water should be in a range of 6.4 - 6.7 and whatever is needed to achieve that can be added to your mix (lemon juice works well if it’s too high).

In our area, the custom mixed fertilizer is about $1.30 a kilo, including the water ph adjustment. Here in the states, they sell a Master Blend with a NPK of 4-18-38, which includes the micronutrients. Since not much will grow with only 4 parts nitrogen, Calcium Nitrate is added to increase the ratio as needed. You will also have to add some Epsom Salt (Magnesium Sulfate). This helps blend the nutrients and prevents algae from growing in the water. To further prevent algae, your plant box must NOT allow any light to filter in.

Just to give an idea of the quantities, for lettuce you would need 10 grams Master Blend, 10 grams Calcium Nitrate, and 5 grams Epsom Salt per 20 liters (approx 5 gallons) of water. Even though the blend is specific for lettuce, we stuck some cucumbers, tomatoes and peppers in the same mix and they are doing well (so far) as Mother Nature allows us a margin of error.

We have watched a series of videos on YouTube by mhpgardener in Virginia. He is easy to understand and rather entertaining. Our first experiment has been with 160 heads of Boston lettuce and a few tomatoes, cucumbers and pepper plants. Below are photos of the experiment and we are extremely pleased with the results. The total time for lettuce is about 60 days. We are planning to do 4 or 5 grows per year of several thousand heads to generate a good income and much needed food for the people in our region!

While this method works best inside a green house, our experiment was done outside. The only problem that may be encountered outside is plants blowing away in the wind or the plant boxes taking on rain water, diluting the mix of nutrients. In our area, rain is usually not an issue this time of year, but we have had few heads of lettuce blow away.

When fully operational, we will be doing some boxes inside a green house, and others still outside, but with a protective plastic canopy fashioned out of flexible plastic tubing. For any communities looking for easy ways to generate income or just food for the group, this Kratky Method is the best we’ve found for minimal time, labor and water. The pickin is easier too (no bending over) and the produce is clean!

Since these pictures were taken, we've harvested the lettuce and the cucumbers are producing. The nitrogen was too high for the cucumbers, so the leaves of the plants yellowed, but the cucs are very tasty!
 

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Odyssey

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That looks very neat, Lilou.

It looks like you have the plastic cups sitting in a hole in a sheet of styrofoam. Is that how you did it?

Oh, I see: _https://www.youtube.com/watch?v=oDYeffYcVkY
 

Lilou

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Odyssey said:
That looks very neat, Lilou.

It looks like you have the plastic cups sitting in a hole in a sheet of styrofoam. Is that how you did it?

Oh, I see: _https://www.youtube.com/watch?v=oDYeffYcVkY

My husband, with the help of a couple of workers, did all the planting. And yes, it is a plastic "net" cup sitting in a sheet of Styrofoam, fit over a box. mphgardener built his boxes out of wood, lined in plastic. But wood is very expensive in the middle east, so instead, we found fiberglass boxes that are used as molds for concrete building blocks. New the boxes are expensive, but we got a heck of a deal on a used lot and they'll hold up better than wood in a hot, dry climate.

I suppose even a Tupperware plastic storage box would work too. To keep the plant upright in the plastic cup, we used pea gravel (small stones) as the filler. I've not personally gotten my hands dirty in this project (yet) but the youtube videos are excellent for all the nitty gritty details. My husband has watched ALL of them, several times. I've watched about a 1/2 dozen, just once.

Heck, you could even use a plastic jug and set it in the window for a small trial run. I'll keep you posted on our project. My boys are in the air now, headed over to plant 15,000 head of romaine lettuce. We donated the first 160 heads, but this next grow will hopefully yield some income.
 

Odyssey

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It does sound like a good project to try out. No damage to the soil, the plots can be moved and you can make money off of all the veggie lovers. You could make good fodder for the critters too.
 

Meager1

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I can confirm your results Lilou.

I am using the Kratky method as well, and have had great success with it.

The beauty of it, is that you can use just about any container that holds water. Then add your nutrients ( I use a homemade compost tea ) then place your seedling in a secure net pot, ( I use moss in mine ), being sure to leave that inch of head space while the longer roots just dangle in the water.

I bought some large but cheap, dollar store containers with lids, they were clear so I just spray painted them dark green and planted in them.

You will need dark containers to stop algae from growing on the inside.

I am also using plastic coffee containers, baby formula cans, and small buckets, and whatever else I can find, they all work very well.

I have mine outside, when it got a little windy I just put a flat stone partly over the net pot on each container and nothing flew away. The simplicity is amazing.

No soil to buy or mix, no garden to weed or water, and no bugs.

You do need to check your water levels every couple weeks when it`s really hot, and you`ll want to add more nutrients maybe once during the growing season, other then that, it really is a set it and forget it, healthy, vibrant and simple way to grow the best "garden" you could ask for!

I highly recommend giving this a try.
 

Lilou

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That is great to hear, Meager1. I'm happy this method is catching on, because it is so simple! Our town has a huge corporate green house down the road from me that does hydroponics. We met the manager a month or so ago, and he said "impossible to grow hydroponics without circulating water". We showed him the photos/videos and explained it and he was truly amazed. Actually he was dumbfounded.

Yep, set it and forget it. That's my way to garden! :D
 

A.K.

Padawan Learner
Thank you Lilou for posting this alternative for growing vegetables. I apologize for hijacking this thread.

I also stumble upon this 'Aquaponics' on the net. I hope it can benefit someone looking for another alternative with some protein thrown in it. Aquaponics is to grow vegetables & fishes together without fertilizers. The nutrients rich water produced by the fishes wastes will cycle to the vegetables tanks for their growth. Then the water will be pump back into the fish tanks once the nutrients are depleted.

_https://www.youtube.com/watch?v=VBspR2p0YYM

_https://www.youtube.com/watch?v=4DMylpQqVKI

A pdf file for the aquaponics setup:

_http://backyardaquaponics.com/Travis/Simplified-Manual.pdf


I found out that the one problem out of this type of setup is electricity to drive the pump that cycle the water between the fish tank & the vegetables tanks. But a simple rope pump may solve the problem.

_http://www.youtube.com/watch?v=3Kbj9Bd-JDY

_http://www.youtube.com/watch?v=C_ZoYK7cjOM

Simple diagram of a rope pump:

_http://en.wikipedia.org/wiki/Rope_pump or you can check out the pictures on Google for some idea.

Just think of it as a form of exercise. :)

Once we merge both together, it will be really useful should the grid goes down or what ever hits the fan. Not sure if i ever use this method(space constrains) but just throw this idea here in case anyone decides to try it.

Failed to see the aquaponics thread below. Sorry for the double post. Mod please remove this reply if deem not appropriate.
 

Lilou

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Hi AK, no need to apologize. I was thinking to talk about aquaponics as well, but I haven't delved into it much yet. We met a retired biologist who sets these systems up and he offered to do it for us, but we are not that far along in our project.

We do stock our water reservoir with fish already, so we'll just have to decide if it is really cost effective and being dependent on a pump, doesn't really entice me much. The biologist says these systems tend to stink - so I may not want to be downwind from it and it may draw big cats to the property!! So while it sounds pretty good in principle, there may be too many draw backs, and fertilizer is cheap in our region.

Thanks for sharing. :)
 
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