Unfortunetley im using tap water
I always leave it out in a 5 Gallon pail for at least 2 days before i use it though. i have just noticed in the last couple weeks that its been happening..started with 2 birdsnests and now my devils hand looks like its dieing. My naso tang died about a month ago and 3 days ago one of my chromis died that i have had for like a year. no signs of issues..i dont know what the heck is going on. all parameters seems to be fine.