Filter size

Ok so I have a 29 gallon tank with the Tetra Whisper EX 30. the only problem is that the outflow of the water is super strong. My axies tend to stay away from one of the corners because the current just pushes them away. I have made an aquarium baffle for the filer but still the current is too strong. I was thinking about getting a sponger filter but I assume I should get one for a smaller tank. My question is what size of filter would guys suggest that
1. isn't too strong of a current
2. is able to effectively still filter my tank



I read about some filters and one said the output was about 80 gallons per hour and another said 80 gallon per minute(which i think might be a type cuz thats super fast)

and as always

Thanks

Have you tried this setup:

Axolotls - Housing in Captivity

As far as filters go, never trust the numbers quoted by the manufacturers, they are always higher than reality.

An Eheim Classic 2215 is quoted as having a "pump output" of 163 gph, and a "filter circulation" of 134 gph.

In my testing, the filter, with media, sitting on a floor with the tank on a stand, was outputting 100 gph.

Canister filters have the advantage of a spray bar with a number of holes, and it can be aimed at the wall, or down, in order to diffuse the output.

Some suggest that the filtration rate should be 4x the volume of the tank, but that was for fish in general; I do not know if they were going by what was on the box or actual measured numbers. I went with a lower turnover rate, as measured in reality, for axolotls due to concerns for current.

You can get sponge filters for up to 125 gallon tanks; I've heard from more than one source to go higher than quoted on that as well; i.e. go larger than what it's for in order to have sufficient surface area for bacteria colonization:

Aquarium Internal Filters: ATI Hydro-Sponge Pro Filters at Foster and Smith Aquatics

I'd guess that the 80 gph filter would be insufficient for a 30 gallon tank, but the filter capacity you need is really dictated by how many axies you have in a tank (as it's really about the amount of waste being processed by the bio filtration).