This is my first post, and I'm fairly new to hydro. I've read some books, notably Jone's excellent "Guide for the soilless grower", but I'm hoping that you guys with some experience can help me sort out my plants issues.

I've got some tomato plants as my learning plants. I'm trying a water 1inch flooded container, and then applying nutrients from the top. I'm using 50/50 mulched pine bark and perlite.

I put some organic nutrients in the mix in the form of cotton seed meal, dolomite, blood meal, bone meal. I've been applying a bit of fish emulsion and now some K2S04 as the flowers start forming.

HOwever, as you can see in the pics, there are spots on the stems - brownish spots. Other symptoms include new growth curling under, and the plants seem to wilt easily, even though my cheapo moisture meter says the material is wet. Overall growth is slow, but I'm not sure if that is because of the relatively high level of shade, or nutrients.

From Jones' book, Calcium deficiency leads to the curling under. But I don't know what the spots on the stem are. The plants seem to have some sort of disease (don't know what) early on, but a spray with neem oil but them back on track.

Any ideas? Suggestions? Pests? They're starting to bud, so I'd hate to lose them now.

I made some calcium sulphate and applied a dilute spray to the leaves today. We'll see...