I've used Hydroclay, aka Leca to successfully grow tomatoes, peppers and cukes, however I've never tried to grow root veggies such as carrots, onions, beets, etc in it. I think its too dense for this and one would be better off using a 60/40 ratio of coco coir and perlite or vermiculite for...
I use the deep water culture method, aka Lettuce Raft. I make the raft from Dow 1 1/2" blue board foam and place my seedlings in 2'' net pots. I use General Hydroponics Flora Grow series of nutrients as well as their Rapid Rooter plant starter plugs to start my seeds in. I built the grow stand...