We have one toilet that does this in between 2/3x weekly cleanings. So frustrating! Atascocita/Kingwood has weird water.
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The only thing I've found that works on these freaky water stains (I think I know exactly what you're talking about...drives me batty!) is The Works. It's blue...you squirt it on around the bowl (concentrating on the stains, or where the water ends at the top), leave it, and it's GONE in like 5 minutes. Even bleach doesn't compare. (It has kind of a strong odor, though, so keep ventilated. The odor doesn't linger after you scrub/flush)
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Strangely, I can only find it now at Dollar General (and it's like a buck and some change per bottle), so I stock up. Try it!
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