I have a tetra whisper air pump rated for 100 gallon aquariums. It has two outlets. Does that mean each supplies air for 50 gallons? Will I be able to use this air pump with my sponge filter rated for 100 gallons, will it have enough air supply?
Personally, I think it would.
I use air pumps that are rated for tanks way larger than what they are recommended for. You don't really need to follow those guidelines as you can put bubblers wherever you want!
My bubblers are also doing just fine in 78 ounces of water, I use those for reptile pools.