stick your finger down about two inches and if it is at all most you need to relax on watering. the roots need to periodically dry out this will promote strong healthy root growth. your plants do not need water as badly as you think they do. Just keep tabs on it and it should bounce back. It could also be your water source i would check the PH it should be around 5 if its not i would get a reservoir for you water and treat it with PH up or down which you can find at your local Hydro shop or online.