I noticed today that my comman goldfish are acting lazy. their breathing is fine, they swim and eat well. Its weird, they swim around then I'll look over at them again and one will be laying at the bottom. It started with one now 3 are doing it. They are breathing normal, water is normal, temp is about 68F. They haven't lost any coloring at all. They look like they are being well lazy, taking a nap and then swimming again, take a nap and swim and so on. Am I being a worry wart? or is there maybe something wrong?