This is a discussion on How do I get get this stain off my tank? within the Beginner Freshwater Aquarium forums, part of the Freshwater Fish and Aquariums category; -->
My dad has had a 10 gallon tank sitting in his room empty for about ten years, but he never properly cleaned it after ...
My dad has had a 10 gallon tank sitting in his room empty for about ten years, but he never properly cleaned it after use. I found it the other day and decided to clean it up and use it for myself. I cleaned it and got it mostly clean except for these translucent white stains on the glass I cannot get off no matter what I do. I've tried scrubbing it with many things, but do not want to use too many chemicals. Does anybody recognize this substance, and does anyone know how to get it off???
Its hard water build up. Lay the tank on that side and pour vinegar so it cover the stain, then let it sit. It may take awhile and a couple repeats to lighten it up. It probably won't disappear completely, but usually it will become barely noticeable once the tank is filled. Otherwise you can use CLR and rinse the tank REALLY good.
I've used CLR on it, but I diluted it because I was afraid to use too powerful of chemicals in my tank. I'll try straight CLR on it this time and let it sit like you said and then rinse it really well. Thanks for the help, I hope it works!
Thans for answering his question. I have a fairly new tank but the water here is so hard that I already have stains on the glass under my light. I was just looking on this forum hoping to find an answer to this very question.