White film inside water storage tank

[dcsnet]

I have a large white plastic storage tank I setup with new saltwater for auto water change. Over time it develops a white/beige film and sort of grit inside the tank? I do have a pump setup to stir it for about 1.5 hours a day. What do you think is causing the film and suggestions to help stop it or at least limit it. Thanka

 

[acesfull44]

This built up in my Brute Cans after a few years. I personally have no clue. Following along for some insight.

 

[mpluta69]

Calcium precipitate? Can you brush it off? In between uses, every vew months, I will throw some RO/DI water in my saltwater mixing tank with some citric acid and run the pump for about 15min to take care of build up but I wouldn't really call the build-up I get a film. I haven't really found a way to get it to stop happening.

 

[Tamberav]

Impurities, organic stuff if you mean the brown sludge that forms on the side/bottom.

It can/also will form a bacterial film.