I went to our one local nursery here today -- and they had several soil-less mixes to choose from. There was one specially for Texas and she recommended that - so I bought it to try. She also has special soil-less mix for seed sprouting - so I bought that.
I took a long fly tape (full of fungus gnats) and she jumped back -- she has long hair and didn't want to get it caught in that ! A couple of the folks there took a look at the bug strip and said they look like fungus gnats. They sold me pyrethenian for that. So all my GH plants have had a good dose of 4/1 water/peroxide, neem oil -- and now pyrethenian. If that doesn't kill them, then I guess I'll just .. give up? Probably not ! Too much invested in this project. Some of the plants are actually starting to do well -- radishes have really jumped. I tried the potato test on the plants and no larvae showed up - which is surprising considering the huge # of fungus gnats in there.
Thanks ya'll for all the info -- I have changed my "soil" -- whoopee !
