Strawberry Cough - Newbie DWC

Filled bucket with nutrient solution and started the air pump (just a tetra whisper 100 between 2 buckets which turned out to be underpowered for this go) Roots started to hit the water late this week, turned lights up a little ~50% @ 16". Humidity dome was left on until the middle of the week when ambient humidity increased, using carboard and white tape to reflect some of the light off the netpot lid. Petiole's are going red, the first node's growth is pretty stunted, meristem seems a bit flimsy but all in all she's growing well and looking pretty good. Nutrient solution in EC=0.4 tap (per gallon): 3g Jack's 5-12-26 2g Calcium Nitrate 1g Epsom salt 2ml Silica gold 2ml Fulvex 1/2 tsp per bucket of Great White Phosphoric acid to get to pH 6 EC=2.0, pH=6