What can I use to get rid of this staining inside of the top left corner of the aquarium?

deeda

Silver Tier VIP
MFK Member
Mar 26, 2008
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Vinegar is fine to use but may not clean it up. It's possible the glass is etched from the hard water deposits or from water splashing if it was lower than the tank rim.

You could also try Barkeeper's Friend or Bon Ami powdered cleansers and make a paste with water and gently rub with a soft cloth. It's much easier to do when the tank is on it's side where the offending stain is located. If you try this method, be sure and rinse with fresh water thoroughly to remove any cleaner residue.
 

Trouser Bark

Dovii
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Nov 7, 2022
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That’s probably calcium and it’ll probably be a booger to remove. The prior owner regularly had that water a couple inches from the top and an air stone in that corner which separated the dissolved solids from the water and etched the onto the glass.

live used something called like CLR or similar that is sold as a bathroom tile cleaner and supposedly is non toxic though I wouldn’t trust that.

lit never worked much better or worse than vinegar for me but depending on what that specifically is it might work better for you than it did for me.
 

TwoHedWlf

Potamotrygon
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Mar 2, 2017
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Straight vinegar or do I need to dilute it? No I only use hydrogen peroxide as I didn't want to mess with the aquarium sealant. My initial thought was the vinegar would be too harsh. But if it's good to go I'll definitely give it a shot
Yeah, straight vinegar. Silicone is pretty resistant to acid, and vinegar on the scale of acids is pretty mild, you can drink it even. It won't hurt the silicone.
 

neutrino

Goliath Tigerfish
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Jan 22, 2013
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Mineral deposit imo. I used white vinegar on a used tank I bought once, which got rid of some but not all of it. I kept wiping it when doing water changes until that seemed to stop doing anything. I thought the rest of it was etched into the glass, which is what it looked like, but it gradually disappeared over time in a pH 7.4 tank on the lower side of moderate hardness.
 
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