what could possibly? the temps are 35c, rh 60%, ph 5.6, ppm 300 and just no EC reading as i dont have any EC meter. and im using the pump and air stone for more aeration and oxygen for the roots.
35c .. drop that alot too 26-28 ish. Put a frozen water bottle in the water to keep it cold. Roots don't like warm water. May need to pull off the stone if still getting rot after fix your temp.