Why aren't my glofish tetras moving around?

[jadewoods]

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.

[Aiken Drum]

Fish get old. I find tetras slow down a bit as they get older, settle in their favourite part of the tank and chill. Im not as active as i used to be and much prefer my spot on the sofa with the cat, rather than going out and about like i used to.

10g is on the small size for black skirt tetras too. A bigger tank with a bigger group of fish would give them a better environment and they might liven up a bit.

[Andy Sager]

When fish have been in an area for a long time, they know where is safe and where the food is and whether there are predators to be on guard for Your fish have been in the tank long enough that they secure that there are no predators going to snatch them up so they have little reason to be more active. Tetras in general also are more active because they like to have a little current in their tank. This causes them to be more active or they get swept away with the current.
Truth be told, I wouldn't be concerned that they aren't swimming constantly and that they have a place they feel secure in. I don't believe adding more Tetras will change this. Changing them to a larger tank with more current would. As Aiken stated, a 10 gal is really on the small side for this type of Tetra.