looks like you gave it too many nutes too quickly as was mentioned above. I have been told and keep to the fact not to give any nutes at all just superthrive until it has six sets of leaves. you are burning em I think. I would flush and enter no nutes at all to let them revive. I may be wrong as I grow in soil but I would assume the rules would be the same. My brother while I was away added nutes too soon and it did just that. I was able to save mine with a good flush with 1/4 tsp of superthrive per gallon of water. See what others say but that would be what I would do if I were you. good luck