What type of filter is best?

Hello, im a beginner and I need help. I have two axolotls each are about 5 inches in a. 30gallon tank. Currently I have a hang on back filter for 30 gallon. But I'm not sure if that's too much. I've read about sponge filters and I'm wondering if that would be the better option. So what's the best type of filter? Should I stick with the hang on or switch to a sponge. And if I do switch to a sponger is there anything specific I need to know about them? Thank you to your time!

It depends how powerful your Hang On Back is. I have a HOB that was too powerful, so I modified it. Sponge filters are what 90% of Axolotl keepers use, and the better option.

I prefer external canister filters for my axolotl tanks, since they provide better mechanical filtration. But I like sponge filters in general, and sponge filters (if driven with an air pump) do not raise water temperature. The sand in the axolotl tank killed the HOB I tried ... I think we must not have been careful enough about not stirring up sand near the intake.

What is "best" for you is more a matter of your preference, as long as the filter meets the axolotls needs (sufficient biological filtration, not too much water flow, doesn't heat water excessively.)

ok thank you for the reply. the filter i have is pretty powerful and it doesn't have flow control. I just want to make sure a sponge filter will really filter well in that large of a tank

Yes, a sponge will work, but it takes a lot of sponge since the axolotls add a lot of waste. So, for a 30 gal tank, get, say, 60 gal worth of sponge, and it should be fine.

Make sure you have multiple sponges, since they wear out and need replacing, and if you have multiple, you can replace them one at a time (with several weeks in between) without having to cycle the tank all over again.

Also, make sure you are cleaning the sponges (squeeze out debris in a container of tank water) regularly. I find I have to clean them out much more often on axolotl tanks than fish tanks. I think it is just the higher bioload, but I'm not sure.

Are you new to aquatics or just axolotls? If you are new to aquatics, make sure you get up-to-speed on the ammonia-nitrite-nitrate cycle. If you are only new to axolotls, note that they are more sensitive to nitrate than more aquarium fish, and so you really need to monitor nitrate.

I hope the sponge filters work out for you. :happy:

Another thing you could do is stick some filter sponge or filter floss around the intake and baffle the out take, again you could do that with filter sponge or floss. I have a Tetra filter for 55-75 gallons on my 55, no out take reduction. I had to remove the intake filter sponge because it clogged almost instantly, but I have a good amount of filter floss on the out take. My axolotl has never had damage to his gills from the intake even though he sticks his face right on it and the outflow is slowed by the filter floss and being pointed to a tank wall. My axolotl hangs around both the intake and out take without stress.

Make sure you have multiple sponges, since they wear out and need replacing, and if you have multiple, you can replace them one at a time (with several weeks in between) without having to cycle the tank all over again.



i am not new to aquatics only to axolots. Im aware of the cycle but l did not know that about axolotls thank you. how often would you say the sponge would need do be replaced?