Grow Hydroponics garden

The Lettuce Raft System - Hydroponics

Each day I respond to more and more emails from people looking for the simplest, most inexpensive means of growing hydroponically. I often recommend the Hydroponic Planter from the previous chapter, however, this "simple and inexpensive" method just isn't complicated enough. So... after giving it some careful thought, a worthwhile solution presented itself.

The raft system is simple, inexpensive ($20-$30 complete) and "complex" enough to satisfy any first timer's appetite for a fun project that actually works quite well. In concept, the raft system does exactly as it says. Plants are grown in Styrofoam "rafts" that float in a shallow pool of nutrient. To keep the nutrient from stagnating, a small air pump is used to deliver oxygen to the solution and eagerly awaiting roots.

Parts List

(1) 14 Gallon Roughtote reservoir (1) Single outlet air pump (Elite 801) (1) 2' x 2' x 1.5" rigid foam sheet (9) 2" net cups (1) 6' x 1/4" air tubing (1) Air stone (1) Small bag of LECA (9) Perfect Starts or equivalent seed starting/rooting plugs (1) 1/4" compression grommet + Hydroponic nutrients

Tools You'll Need

Electric or battery powered drill - 3/8" or 1/2" chuck 1 7/8" hole saws for cutting plant sites 3/8"drill bit for drilling grommet hole Jigsaw or coping saw for cutting foam Razor knife for cutting tubing A pen or marker

Author's first prototype raft system made from a plastic garbage pail. Plants shown were grown under a 95W 6500K fluorescent bulb which is said to provide similar output to HID systems yet without as much heat. Not bad for three week old lettuce.

Step 1.

Trace the outline of your container onto the styrofoam sheet as shown here.

Step 2.

Measure the distance between the outer edge of your container and the inner wall (measurement 'X')

Step 3. Be sure to cut the styrofoam 'X' inches smaller than your outline so that it fits neatly inside the container. After a little bit of additional trimming, you should have a perfect fitting "raft" as shown here. Make sure it can move freely up and down inside the reservoir with it full of water since the pressure may deform it a bit. If this is the case, simply trim away until you can get from 4-8" of up and down movement. This is very important for this system to work properly.

by Daniel Mendes