Removing dried vermitid shells

[rsach]

What's the best way to remove vermitids shells on the overflow box of an empty aquarium? I have tried spraying citird acid and also tried spraying hydrogen peroxide and covering them up with paper towels. They turn white and I can scrape some of them but the others are pretty hard to remove. I had a heavy infestation.

 

[Fish Fan]

If the aquarium is empty, try filling it with tap water, adding a small pump and a stiff shot of vinegar or citric acid, and let the pump circulate for as long as overnight or longer. The 'snouts' should just dissolve in the acid.

Good luck!