How large an air filter for 2 axies?

[ellena]

I'm going to be getting 2 juvenile axolotls. Tank is 120l. I'm going to make an air powered filter. How big a container for the media would be suitable for 2, thinking about when they're full grown, not just while they're little?
Thanks

 

[dragonlady]

For 2 adults, I'd say that you might want to consider making a canister type for better efficiency, plus it would take up less floor space than the internal filter you are planning on building. Just a thought.

To answer your question, I don't know exactly, but maybe a liter size? I think it will be the size of the air pump that will determine the efficiency. Air pumps do tend to be a bit loud, especially the larger ones. If you could, I'd get a Rena brand - those tend to be a little quieter.

 

[ellena]

Ooh, a canister; that sounds technical!
The type I have made before are a container with holes in the base and one in the top through which is threaded an airline. It's weighted down with gravel and then filled with whatever media you have.
I made the last one from a tupperware style tub and was thinking of something tall and thin like maybe a spaghetti container for this one so as to take up as little space as possible.
Is a canister very much more difficult?
What size of airpump would you recommend? It's going to be in a classroom, so noise isn't as much of an issue.