Bryan, getting some larger tanks with a little more carrying capacity might help, 1 and half gallons is not a lot of water, remember they are releasing nitrogenous waste products into the water and if its not properly filtrated, toxic levels of ammonia and other metabolic byproducts are going to build up. If you cant go with larger tanks, them you had better change the water daily, remember the temp, its really important that you dont shock your fishes. I cant think of anything from the birds that would be toxic via the air, but then again Im not an expert either.

Great blogs for help and information.