alright adam, i guessed as much and i'm goona add another air pump with a air-stone on the end to further aerate the water/nute's
ur right it is residue from the caly pebbles...they were all washed out before going into the pot but haven't cleaned/flushed it since. is there a regular time when tanks are flushed providing a completely new supply of water/nute's?
just got some nice cuttings today as well so will be getting them in the nft tank over the next day or two so i'm well happy and looking forward to powering up them hps
