I've had my tank for about two years now. It's only 10 gallons and has now 5 smaller tetra glofish and some shrimps and snails and I keep it at 80 degrees Fahrenheit. The tank is healthy, I do regular water changes and cleaning, have the water tested once in a while and have had no problems since I first started the tank. But for some reason my fish won't move. For like a year now they all have their own spots they like to hang out in the tank but they just sit there all day they only swim around when they've just been fed. I don't think they're sick, there's no visible symptoms besides this inactiveness and they've been like this for about a year, since just after I got them. I've just added a fifth fish so hopefully this helps. Any ideas? Not sure what to do.