Hello, I got used tanks from a friend. I got 2 55g tanks, one for amazon/tetra, and the other for saltwater fish later next year.
I also got a tank that is smaller than a 5g. In measurements it is the same height and width as a regular 5 gallon tank. In length it is noticabely shorter by at least a couple inches. I guess maybe it is a 4 gallon tank? Anyway, it appers that water had sit in it unfiltered for a while. There is a noticeable water-line (where the water level was when the tank had water in it), and I can't scrub to the top of the water-line.
It is smooth were it had water, but rough and non-see-through above where the water line was. The water-line is at a little over 3/4 of the tank high. It looks ugly, and no matter how long I scrub it, or how hot the water, it just isn't coming out.
Is there a chemical I can use to clean out this tank? I am going to put Tony, my betta, in it so I want it to be perfectly safe. My mom suggested I use Clorox Bleach but I am not sure that is safe.
BTW the 55g tank is a total mess! I haven't started on that one yet, but I can't wait to see schools of tetra swimming around in a nice, well planted aquarium.
My immeadiate issue is the cleaning the "4g" tank. Any cleaning tips on the other tanks would be very helpful!