Drained pool, refilled, still have iron - where could it be from?

[Orion7319]

I do have a heater, it is a Hayward with a nickel-copper exchange. It is only five years old. It seems unlikely that it is the source but I'm running out of places to look.

Yes it seems unlikely as when those go you get copper staining.

Mine is an older home, no PEX, copper and PVC instead. Plus, as you saw, the fill water from my spigot I use came back negative.

Mine is an older home as well and I have a mix of plumbing like that. I believe that one of my tubs must have some old galvanized pipe somewhere in line as sometimes I get some rust colored water out of just that particular fixture. If you are going to drain your pool again, try different brands of salt and CH increaser obviously…

 

[poologant]

For anyone who might read this thread in the future, I tested for iron in the salt by creating a salt solution using distilled water and my salt (Diamond Crystals Solar Naturals). I mix it at a concentration about 33 times what I would put in my pool. So, for my pool starting with zero salt that would be about 450lbs. My test salt solution would be mimicking adding about 14,900lbs of salt. My reasoning for doing this is if my test solution came back without any significant iron using 33 times what I would have used, then my salt was fine.

The test (Taylor Midget Comparer) MAY have been as high as 0.1ppm (but honestly I'm not sure it was even that high - color tests can be tricky). So, at worst looks like I would have added 0.003 ppm to the pool.

So, the salt is clearly not an issue.