Considering my second set up. What are your opinions on the best filter to go with on a 20g l? i see many suggest sponge filters and I know nothing about them. What are the pros and cons of this type of filter and any other recommendation and their pros and cons would be greatly appreciated.
I have 7 in my tank. I was debating between 6 and 8 and the guy I ordered from convinced me on 8. 7 survived the trip. They started spawning within a little over a week of being in my tank. Lots of fun to watch.
Sponges are easy, I love them for small tanks. They do plenty of bio and I vacuum out the solids when I do water changes, so I don't have another filter to clean. But I have several small tanks, 14 to be exact, so I don't want 14 HOB's to have to clean. If you just have one, it's not a big deal. Might save you some vacuuming of the sand.
Well at the time I was making my decision about HOB vs. sponge for my tank I hadn't dialed in a quiet enough air pump for my liking (I am picky about noise in my office) and the sponges I have were too big for a 20g long. It was really a decision based on what I had on hand.
A sponge would fit better with my background though. As it is I have to kind of tweak the intake tube a little even though I bought a background that sits flush and has a max depth of 1.5" (one of the shallowest 3D backgrounds I could find).
By the way I received a Million Air air pump today. It is quieter than the Rena pump I was using (I use sponges in my 60g).