I recently set up a new small aquarium for my betta. I used some black gravel that I had leftover from another aquarium. I can't remember if the gravel was ever in the aquarium or if it has never been rinsed. Regardless, I rinsed it very well before putting it in the aquarium. My fish has been in there for two days now and I just now noticed there was glitter on the plant... The black gravel has a shiny sheen to it and apparently glitter is coming off of it. I cleaned the aquarium and rinsed the gravel what felt like a million times with hot water. There's still glitter -_-" I'm almost positive it isn't harming the fish as he was in it for two days and is perfectly fine and very active. I don't know how I could of rinsed it any more thoroughly than I already did. Is there anything else I can do to get rid of it? I assume it will eventually clear off because my other aquarium with that gravel has no glitter. I don't remember it ever showing up in that aquarium.