If its glass... get a big tough algae cleaner or just a tough pad (brillo) and scrub and wash it out a lot with normal tap water ( dont worry about treating the water. Chlorine will kill off any bacteria you dont want and there probably isnt any good really in there. ) All i can say is scrub it lots and rinse out and scrub anything in the tank.
When filling with proper water use a water treatment like a dechlorinator and that will remova any from when you were washing it out.
If its acrylic it will scratch easy but i bet its not so...
When filling with proper water use a water treatment like a dechlorinator and that will remova any from when you were washing it out.
If its acrylic it will scratch easy but i bet its not so...