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
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.
Step 4. Layout the grow sites on your styrofoam raft and use a hole saw to cut them out. If you don't have access to a hole saw, you may be able to use a utility razor to perform the same task albeit more challenging!
Step 5. Mark off the lowest point your raft will reach inside the container (due to the wall taper or internal obstruction) so that you'll know when to top it off in order to prevent the nutrient level from dropping away from the bottom of the raft and leaving your plants high and dry.
Step 6. Drill a 3/8" hole in the bottom wall of your container and insert the 1/4" rubber compression grommet. Pass your air tubing through the grommet and attach to your air stone.
WARNING! YOU MUST mount your air pump higher than the maximum water level in your container to prevent back flow of nutrient solution through the air tubing and into the pump.
Step 7. Time to plant your favorite seeds! I used a scissor to trim the bottoms off the Perfect Start #2's since they were just a bit too long for the little 2" cups I used here. Use LECA stones to back fill around the seeded plugs and place them into each of the grow sites in your raft.
Step 8. Fill 'er up! Add water, nutrients and plug in your pump, your raft garden will start gurgling and your plants will grow in no time - don't forget to give them plenty of light and top off the nutrient solution every time it drops 2-4" or so. It's also a good idea to completely flush and clean your raft system every other harvest using a 10% bleach solution and scrub brush.
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