Sponge Filter for 20 Gal Long

[Alec]

What sponge filter should I use on a 20gal long? Should I use ONE medium filter or TWO small filters?

[Jimmy]

I don’t think either or is going to provide more benefit but if you run two it would be easy to start another tank in the future

[Alec]

On 10/17/2022 at 5:12 PM, Pepere said:

Running 2 also allows one at each end of the tank increasing water circulation.

This was my main concern -- lack of water movement since it is a longer tank. 

[nabokovfan87]

On my 29G I run 2 large ones.  I mean, it's a sponge filter and you're going to see it. If you're fine with that then I would just use the biggest one you feel like using.  In general with most/any "long" tanks, having one on each side does really help out with flow and circulation.

It's honestly a preference and I would base that choice upon what you want out of the tank.  If you want to have good flow, run 2. If you want to try to hide it, run 1.  The only concern between a 20L and 29G is the vertical height, so you can check the dimensions on the store for comparison.  Depending on the scape as well, making them easy to clean is the other consideration.

[Alec]

I might do two smalls - one in each corner. 

[AllFishNoBrakes]

My 20L has 1 small sponge filter, but it is a shrimp/crayfish/snail tank. Just goes to show the possibilities are endless and you can do what makes you happy 😊