My tank is healthy and runs at about 80. What is the trick. I have tied it to different things and it will eventually die. I just would like to grow something flat to cover a item in the tank. Some moss won't even grow well in my tank. Fissisen was popular here for awhile. Did others just give up growing it also?

I think fissidens prefers colder temperatures. 80 degrees might be too high for it to thrive.

80 degree temp shouldn't be an issue. Mine grow fine for me in 78-84* in the summer months. I don't know the exact water parameters but mine grows very well in hard water, EI dosed, high light, and CO2.

Mine grows fine at 82F.

Weedy in fact.

moss is a slow grower do u have co2? what type of lights? i keep mine in the low 70s (noheater) and its growing as fast as my flame moss. are there any ferts for them to use kinda dumb ? to ask but gotta ask it. if your tieing it to things is it dieing at the base or the whole thing? base means it needs light whole thing means there is something else that needs looking into imo

fissidens are fast growers with medium light and co2
i toss tons of the stuff, doubles in size every few weeks
the stuff grows too fast lol

Mine will only grow in low light (ie. 1 t8 on a 12" tall tank) with no co2.. Couple weeks later I have more than I know what to do with. I tried it in my highlight co2 injected tank and all it would grow is algea and BBA on it..