Lettuce Raft System
I wanted to try this after seeing pictures of a few systems (medium to large size) that looked enticing, not to mention inexpensive to build and relatively easy to maintain.
Found a cheap source for Styrofoam (a Drywall company), had a 24x30" box and some 4-mill plastic to line it with. I also have several shop lights, a good size air pump and lots of soaker hose, plus a few left over horticubes, net pots, lava rocks, nutrients and seeds. Basically, it was only going to cost to run the 4 40-watt bulbs.
Mixed up some nuits (Garden-Tone dissolved in water) and adjusted the tub of water to about 800 ppm and the pH to 6.0.
As I am apt to do, I screwed up by trying to use some Fish Emulsion to boost the N level. Resulted in a lot of foam and slimey gunk on the roots. Emptied the water, washed off the roots and restarted. The plants were slow to respond at first but maybe a week ago showed signs of survival. I checked them this morning and they are 4x the size they were a week ago.
I have room for three 12' long trays of plants (at the spacing I'm using that would mean 216 plants. I would love to get the grow cycle down to six weeks.
Next - to learn how to grow enough tomatoes to go with the lettuce! Then tackle cucumbers. And, can one grow carrots hydroponically?