I have adjusted the air valve to make it more “bubbly” but perhaps you guys with your vast knowledge can tell me a good rule of thumb, it seems all the same to me, not the two cups output no matter what… thanks. Kenn Novice marine aquarist I love your site. Reading the articles and advice has helped a great deal, but I’m still confused about a couple of things. I have a 55 gallon with an Amiracle wet/dry, built in protein skimmer (that rarely works). The tank has about 3 inches of sand/crushed coral, and I’ve started to add live rock slowly (about 15 lbs right now). The tank has been up and running about a year, with a featherduster, bi-color Pseudochromis, a clown and 2 other small damsels, and 2 hermit crabs. They’re all healthy, but every time I try to add a fish or two, something happens to the new ones. Always the same pattern. I take a long time