Algae, biofilm in axolotl tank?

[axolotle42]

I posted a thread a bit ago saying about biofilm in my axolotl tank but now I'm not entirely sure it is biofilm because it says biofilm feeds off of waste but I dont have any leftovers or waste In my tank and it doesnt always look like the biofilm in pictures I search.
it is slimy and coats my tank walls, it also hang onto my decor and sits on top of my tank.
for the stuff on top I've been using the paper method to remove it every so often but it always come back.
any ideas if this is biofilm/how to remove it? (pictures attached) thank you :]

 

[axolotl nerd]

I posted a thread a bit ago saying about biofilm in my axolotl tank but now I'm not entirely sure it is biofilm because it says biofilm feeds off of waste but I dont have any leftovers or waste In my tank and it doesnt always look like the biofilm in pictures I search.
it is slimy and coats my tank walls, it also hang onto my decor and sits on top of my tank.
for the stuff on top I've been using the paper method to remove it every so often but it always come back.
any ideas if this is biofilm/how to remove it? (pictures attached) thank you :]

the way i dealt with this was just frequent water changes. i took out all decorations and washed them throughly as well