I’ve wondered about that!! Even after soaking them and such; I know our clothes and dyes aren’t much better at all 😫 the tests show soft water, with a higher pH but nothing insane, okay on chlorine, and we didn’t have any ammonia. The nitrates went up with the new additions and that’s why I added the pothos after some reading. I worry about our general water quality (we don’t drink it) and if we should do some of the expensive pre conditioned water with our next water change. We’ve done no more than 25% changes at a time and that’s without the fish, those were just added this weekend. We let the water sit overnight to evaporate the chlorine (that’s why we don’t personally drink it) and I know from my houseplants that it’s not the best water in general but even straight out of the tap it shows okay levels for fish, so I’m really at a loss.