tdgforbes73
New member
Recently i have noticed my tank (2ft containging 2 axis) has begun to smell . Originally i thought it was because the sand substrate had begun to turn black. So I took all the sand out and replaced it with brand new clean sand. However the tank still smells so now i have started doing regular water changes every other day of around 15-25% to try and get rid of the pong! But none of this seems to have helped! Why is it smelling!?! and why is the sand turning black!?! Please help, Thanks!