Sponge or UnderGravel ?

[beatking]

I have both filtration systems ready to go (two medium sponge filters and an undergravel filter ) Which would work better for a 29 gallon tank and why? Thank you

Steve

 

[Slaphppy7]

I'd never use a UG filter, in any tank...too hard to maintain/clean = gunk buildup = nitrAte factory

 

[Byron]

I have over the years had some tanks with an undergravel filter, and I have had several with a sponge filter, and others with an HOB and canister (larger tanks). The fish species is a determining factor, but I will just say that undergravel filters have issues and I have not used them for years. First, you need gravel and cannot use sand, which limits fish options (cories, for instance, must have sand to be at their best). UG filters draw the detritus into the gravel bed and it clogs up there. Siphoning some of it out with a tube down the filter air return does help, but you cannot really "clean" the filter bed without dismantling the tank. There are also species of anaerobic bacteria and these will not manage with oxygen-loaded water being drawn through the bed.

What fish species are intended? Flow from the filter impacts fish, some need minimal, some more. Also, are live plants intended, as they impact filter needs too.

 

[Colin_T]

Undergravel filters are fine for most fish and are easy to clean. Just use a gravel cleaner every week when you do a water change. They are no more a nitrate factory or home for gunk than any other type of filter. You clean sponges and power filters, and you should clean undergravel filters.

However, as Byron mentioned, we need to know what fish you plan on keeping. If you want cichlids, they might dig up the substrate and stop an undergravel filter working properly.

If you want bottom dwelling fishes, then sand and a power filter might be a better choice.

If you want hatchetfish, then sand or gravel and an air operated sponge filter is the go to.

 

[beatking]

Thank you all. I plan on keeping community fish ie. neons, danios, platys, rasboras, etc.

Steve