Air pump for sponge filter

[Lilibugz]

I’m upgrading my Spanish ribbed newts from 20 to 40 gallon and need some help deciding on an air pump for their filter!
They have a sponge filter in there that supports up to 50 gallons so it should be a good size for their new tank! The problem is their current air pump only supports up to 20 gallons so I’ll need a new one. I’m currently using the tetra whisper which has done well so I plan to get the same brand.
They offer one that’s made for 20-40 gallons and one that’s made for 40-60 gallons
Both support a 40 gallon but would one be better than the other?
Thanks!

 

[Lilibugz]

On a side note I may end up adding a second sponge filter, depends if the single filter is enough to maintain water quality! I’ll just have to do water tests and see once it’s all set up!

 

[Anonymous Salamander]

Go to Amazon and find the strongest affordable one you can find, and make sure it has an adjustment knob. There are some sizeable cheap air pumps that could push enough air to run sponge filters to multiple tanks. There are no wrong answers with air pumps since they all do the same thing so I wouldn't worry about being TOO particular.