I have two 10gal tanks that I'm going to put double sponge filters in. I want to get a two outlet air pump. Should I get the 150gal that does 80 GPH or the 50gal that does 30 GPH. I'm also putting another double sponge filter in my 40gal Tall tank and will get the same pump. I know with filters, bigger is better but I don't want to blow them out of the water.