is airstone/pump needed for 1 fish?

i have 1 small pygme cory cat in the tank with my newts to clean up what ever they don't eat, so my question is do i need a airstone for him or should the little submergable foam filter a good enough air supply?

 

Sponge filters are generally run off of an air stone. As long as the surface of the water is being agitated and the cory isn't gasping for air at the surface (they do occasionally go up to the surface to gulp air, but it shouldn't be more than a few times/day) there should be enough oxygen.

Out of curiosity, approximately how many gallons of water does the pygmy cory have? Also, you should be aware that cories (and especially pygmy cories) are very social fish and can become extremely stressed if they're kept singly. They really do best in groups of at least 3, but preferrably 6 or more.

-Chelle

 

the cory is in a 15 gallon that is filled up about 3/4ths.. so about 12 gallons.. i added 2 more cories today along with another plant. which was carrying snails :x

 

i dont think the tank is getting enough oxygen... ther cories are just sitting on the boottom with there gills going quickly, but they rarly swim to the top of the tank for air..

 

Some extra aeration wouldn't hurt then.

You might also want to check your levels for ammonia, nitrIte, and nitrAte. I don't know how messy newts are, but sponge filters aren't the most efficient filtration.

-Chelle