Drooping leaves on tomato plant

4:02 am in questions, Seeking Advice, Water flow by Niklas Hjelm

Hi! I’m having some trouble with my tomato and hope someone can help me. It’s growing well in a drip irrigation system under a LED light but some of the leafs are really soggy and drooping. It’s sitting in a rootit cube with clay pebbles around it. EC is 2.5 flora series with PH of 6. I’ve tried experimenting with the amount of water but cannot seem to get it right. Right now the water runs 4 x 15m with 4 hour intervals. Can someone help me? Thanks