Thanks guys. It is common practice in Long Island to add zinc orthophosphate to the water supply to control corrosion in the pipes. All of Long Island uses well water and it corrodes brass very fast. The zinc forms a film on the inside of the pipes to protect them. The brass screws inside valves just crumble.
I have resins now that specifically remove zing, I get it from "The Filter Guys" I don't remember what type it is but I need to orser some more.
This zinc is what stopped my from using tap water like I did for many years. The first time they added the zinc I lost all my corals also and that was about 20 years ago. I don't think it is too much of a problem every day but if I happen to change water with a batch of water just after they add the chemical, my tank is in trouble. It seems that my RO/DI does not remove enough of it in those cases. It also happened to the large LFS a few blocks from my house the same time it happened to me.
Newman blue devils cost $7.00 in 1971 in Manhattan, thats like $50.00 today. I initially filled my tank with water from the Long Island Sound as there was no ASW for sale then. There was also no live rock or any rock, we used dead coral skeletons for decoration and we removed then every couple of weeks to bleach so they were pure white. All tanks looked like that.
I added livestock then like I do now but we had to keep copper in the water continousely because everything had ich. ZThe tanks were not very healthy due to not having enough bacteria and there was no salt water food available. There was nothing in print, no books and no computers so no internet. No fish forums, and no one with a salt tank, except me. I bought the first blue devils the week they became available for sale 40 years ago next month.
I change about 20% of the water 5 or 6 times a year and I only add homemade 2 part calcium and Lugols Iodine.
The first 5 years the tank was in smaller glass, here it is circa 1972. You can see the bleached corals and the blue devils.
I got them to live 7 years and they spawned for many of those years.