I have these two 2gs that I use as QT/hospital tanks, and I've been doing at least two 100% changes a week. I have been thinking about making some DIY sponge filters, as I already have air pumps sitting around and my local store sells tubing, valves, and air stones. Not quite sure how exactly to make one. I know I need some sort of tube for the air/bubbles to go up? I have no experience with sponge filters
Or maybe it would be cheaper/easier if I buy one? I know I'd still need the tubing and valves.
Though this might end up being moot if I finally rip apart and divide my 15g once I get more sand. But I'd like to improve my 2gs anyways.