Im clueless to this problem. -120W CFL @ 3" -DWC -29C (84F) -35RH -270PPM Lucas formula +Rep for solving it.
How many times a day r u watering it. Possible over water. Too hot as well. Need good airflow and knock the temp down about ten degrees. Also u may have a magnesium deficiency.
Thanks alot for info man I water once a day(topping it with plain water at same PH as solution) It is in water the whole time, its deep water culture with air bubbling from a big airstone. (200L p/h) Heat is a problem