Grow Bags Combined with AquaValve

Following is a brilliant design from Ben Frimmer of Philadelphia.  Ben's system combines Grow Bags with a wonderful product called an AquaValve. (AquaValve's Home Page).   If anyone can figure out how to make an AquaValve (an inverted float valve) on the cheap let us know.  Read here and here to learn how the AquaValve works.  Here's Ben's system in his own words:

When I saw that you are using reusable shopping bags on your website, I had to get in touch!!! With that said, here's a design that may just help you out...

Click to enlarge

1st thing: If you haven't heard of the Aquavalve or an Autopot, check them out on the web. They make an INVERTED float valve. This creates a "flood-and-drain" effect, allowing the soil to dry out, increasing air flow, stimulating vigorous root development, preventing "root rot" and other diseases, etc. This too attaches to a gravity fed automatic watering system....

So here's how to build it:

1. Place "Grow Bags" into any LEVEL container that doesn't leak (only needs to be about 2 inches deep). Can be as wide as you want as long as it's level. This will serve as the "floodplain." Get creative and keep it cheap! (lids of plastic totes, a dirt "box" lined with a garbage bag, any container will do as long as it doesn't leak!)

2. Use the plastic from garbage bags to cover the Grow Bags and make your X's. (I use string because it's cheap and easy) Just make sure to only cover the top and not the sides. Your babies need air!

3. Place Aquavalve onto bottom of "floodplain" and attach 1/4" tubing to gravity reservoir and Aquavalve. (Make sure the reservoir is 2-3 feet above your level floodplain or it won't work). Glue the valve down, place a rock on it, anything so it doesn't float.

***At this point, your reservoir is going to flood the "floodplain" with about 1 inch of water. The water wicks into the Grow Bags, the plants drink what they want. When the water level reaches about 1mm, the valve reopens and the floodplain floods again. So you can be done at this point, just refill the reservoir by hand when it gets low (about once every 2 weeks). But if you're like me and you're too lazy to do that, go to step #4....

4. Go to any hardware store and buy a replacement float valve for a toilet. (less than $10). Hook that up to any household water supply line, and secure it to your reservoir. (Check out how your toilet works to see exactly what I mean). As the plants drink the water, they will "flush" the reservoir and it will automatically refill itself! You never have to water again. Ever!

My system at home has 32 Grow Bags, set out as 2 separate 5'x5' "floodplains", 16 Grow Bags and 1 Aquavalve in each one. The system is in our greenhouse, so we grow all of our own produce year round! The whole thing, all materials included, cost me $47 to build. ($30 of this was purchasing the Aquavalves and the tubing!) I have used it for 3 growing seasons, and it works flawlessly. The only maintenance you need to do (besides pruning and harvesting of course) is flushing the lines and replacing the soil / fertilizer each growing season.

I use COMPOST TEA as my fertilizer and it works amazing, season after season. Just put a few handfuls of compost into some cheesecloth and place it into the reservoir like a tea bag. That's it! Just replace it with new compost every 2 weeks or so and put the used compost back into the pile or in your grow bags. Cheap and reusable liquid fertilizer. Organic farms have been doing this for centuries!

Here is a list of materials I forgot to put on the diagram:
1.  Aquavalve - $25 USD
2.  1/4" Tubing - $2
3.  Grommett - $1
4.  Standard Toilet Float Valve - $7
5.  Garden Hose - $5
6.  Rubbermaid 25-Gallon Reservoir - $8

So all the materials, most available at your local hardware store, cost $23.  You do have to order the Aquavalve online.

The rest, like Grow Bags, Potting Soil, Compost, and the Floodplain are up to each individual's ingenuity to get and/or build.  In my area, Philadelphia, I got all of these for free.  

{A cheap idea for a floodplain is to dig a small 2 inch deep "box" in your backyard using a level.  Then you can go to the local Walmart / Home Depot / Costo, etc. and take all of their used Forklift Palettes.  Then you can line your "box" with free wood, and place a layer of garbage bags on it to make it watertight.} 

Anyway, you get the point.  All you need is a level surface for the Aquavalve to do it's thing.

Ben & Becca