sucker marks on acrylic hex

[tramca]

I have white circular sucker marks on the sides of my acrylic hex tank, obviously caused by the heater holder and thermometer. They wont rub off even with pressure and wont scrape off without scratching the surface.

Any ideas anyone?

 

[FroggyFox]

Is it a tank that you have fish in? or an empty tank that you're trying to clean up?

If its an empty tank I was going to suggest trying vinegar or some really really hot water soaking it in...the white color sounds like its just a hard water stain...unless its actually scratches??

 

[tramca]

I think they are hard water deposits. It's a tank I had running till 3 days ago with a male betta in but put him in a divided tank with 2 others, but am cleaning it up with a view to selling it.
Will try the vinegar and let you know froggy, thanks.

Tra