Katch Fishaholic Joined Aug 13, 2010 Messages 580 Reaction score 0 Location Cornwall Aug 26, 2010 #1 Just wondering if my Nano is meant to have a small 4mm hole about a 3rd of the way down the front of the filter box back into the tank? What's it for? Should I plug it?
Just wondering if my Nano is meant to have a small 4mm hole about a 3rd of the way down the front of the filter box back into the tank? What's it for? Should I plug it?
