Water Line Scaling

[reefer1]

Although there's plenty of surface movement, a white/clear line seems to develop at the surface on the tank glass. I've tried to scrape it off but it takes a lot of pressure.
What causes the scaling at the water line of a tank?
What's the best way to remove it?
Thanks

 

[Randy Holmes-Farley Verified Community Expert]

Can you raise the water line so it is hidden by the plastic or whatever encircles the rim?

It is probably calcium and magnesium carbonate that remains when a little evaporation occurs. The other salts from evaporation will more readily redissolve.

 

[reefer1]

The tank is rimless. It's only visible because I know it's there...

 

[Randy Holmes-Farley Verified Community Expert]

Aside from minimizing evaporation and keeping calcium, alkalinity and pH on the lower end, you'll probably have to live with scraping it off.

 

[reefer1]

Thanks

 

[Randy Holmes-Farley Verified Community Expert]

You're welcome.

Good luck!