Eau or anyone, please help! I have a trickle of brownish water marks trailing down my wall from one corner of my tank! The other day it was dried, now it's damp and I can feel wet on the bit where I can squeeze my finger round the back of the tank. Could there be a leak?? What the hell do I do if its leaking? No visible cracks. I have dried the water bits with a cloth, so if it becomes wet again I will know there's a leak. I did a water change yesterday so am hoping it it cold have spilled.... But aware I'm clutching at straws :-(