Can some one help me id what this is on my glass

[Neyteri]

yes i took over my old filters i did give them a clean though obvs needed the bacteria though so couldn't go and clean it all with new water etc and i can't move my fish out and re cycle this tank so that goes out of the window i now just have to find a way to either control it or kill it but not sure how it seems near impossible to kill water changes don't affect it salt doesn't seem to affect it either i guess there is no other option then just simply remove it and keep that up and hope it doesn't get as bad and keep trying to find a way to kill it i will clean my filters again shortly and then see if i can reduce it more do a couple of water changes see if that might at least slow it down though if anyone knows of a way to kill it please do tell