Worried about my guppies, I have 2 red blonde male guppies in my 10 gallon tank. I recently installed an air pump/air stone into the tank and the first day they seemed fine and even went to explore the bubbles and swam around in them together. But the day after they are hiding behind the filter and only come out once in a while. They did come out when I fed them. I do also have 5 neons in this tank and they are acting totally normal. Any ideas what's going on?