my friend and her mom, have a few aquariums because they have a snake, a spider, and a turtle, they are all in aquariums but they have an extra that they dont need anymore, they said i could have it but its basically encrusted with algae. my friend said its past the point of being able to scrub it off i was wondering if there is anything that would take it off such as CLR or bleach or vinigar or somthing. and after i used this chemical or w/e if u rinsed it out and rubbed it down well would it be safe for a fish. id like to give skye a little more room, or purchase another betta, hopefully a crown tail. thanks