Try using a little less fertilizer. I would have to say that your problem could be many things, however I would start by using less fertilizer. Leaf curl is a sigh of over fertilization. Over watering is one of the biggest problems for people new to Hydroponics or gardening. The plant is generally more vounerable to over watering in early stages of growth.
Tomato plants grow really well in hydroponic systems.
You want to be careful when the plants are young not to over water. This can cause problems. Also using to much fertilizer can cause problems as well. All rights reserved. All rights reserved.