How to Make Gravity-Fed Hydroponics

Drill a 1/2-inch hole in one end of the bin, just above the bottom. This is where your nutrient solution will pass in and out of the bin.

Put one end of the tubing in the hole so that two to three inches are on the inside, and the rest is outside of the bin. Seal it in place by using a liberal amount of the silicone sealant. Apply the silicone to both the inside and the outside. Allow it to dry for 24 hours.

Make a 1/2-inch hole in the bucket, and feed the tubing into the hole. Let a few inches of tubing protrude into the bucket. Seal it in place, using the silicone on both the inside and the outside of the bucket to assure that it won’t leak. Let it dry thoroughly.

Cover the open end of the tubing inside the bin with a piece of nylon screen and tie it in place with plain cotton string. You can also use a plastic zip tie if you prefer. This will keep the perlite from getting into the tube.

Set your bin on a bench or table. Locate it where your hydroponic plants will get plenty of light, such as on the patio. Place the bucket below it. The bin should sit at least 18 inches above the top of the bucket.

Fill the bin with perlite. Scatter your seeds on top of the perlite and lightly press them into it, so they are covered but not deeply buried.

Add enough nutrient solution to the bucket to fill the bin almost to the top. Raise the bucket to at least a foot above the top of the bin. The solution will flow from the bucket into the growing tray. Let it stay about 10 minutes, then place the bucket below the growing tray again and the nutrient solution will flow from the tray down into the bucket. Repeat this process three to four times per day. Use four if the weather is hot and dry, three if the air is very humid.