Omard, my tank's are between 79 and 81 degrees and I am having a hard time keeping mine in check. Its growing and spreading great, which actually doesn't bother me because I like it. I have found that it grows and spreads faster if it has lots of light and good water conditions and lots of flow. I have it in all 3 of my Nanos and the only one it is slow growing in is the 16 which is 18" deep and has PC's on it. In my 10 and 20 it has pretty much spread everywhere. As far as keeping it in check, I have found recently that even keeping it on a rock in the middle of the sand really doesn't work, like a Kenya tree, mine just dropped some arms or heads and where they landed they grew. didn't know this till the other day when they got big enough to reach above the rocks at one end of my tank.