After 8 years of peaceful pool ownership, a monster has arisen from the deep to torment my once sunny, restful days. I know not from whence it came, but it calls itself Iron, and it's kicking my sorry A**!
Round one: followed instructions for AA treatment that I found here. AA from Leslie's and 2 bottles of Metal Magic. Worked like a charm. Less than a week later, stains reappeared. Yes, there were lots of swimmers, and yes, I raised the FC after a party, although I did not shock.
Round two. Followed the same procedure. Clean liner lasted about a week this time. I can't figure out what made the staining come back. Using the heater? FC above 3.0? I haven't shocked all summer, and PH has not been above 7.2. Doesn't make sense.
Somewhere in between all this I used Metal Free - MISTAKE. Cloudy pool for two days. Like milk. Yucky. But it did clear up just fine.
Round three. Decided to forgo the ascorbic acid, because staining was light. Followed instructions on the Metal Magic - dropped FC, added two bottles of sequestering agent, then added a culator pillow. The Metal Magic alone took longer than the AA- maybe a few hours - but did the job. Thought I was in the clear. But a week or so later, Iron Man was back. Light stains at first, so I thought, you know what, I'll just deal. But it got worse and worse and worse. Finally, I couldn't take it any more.
Today was round 4. Stains were heavy. Still can't figure out what keeps causing the sequesterant to fail. My FC has not been above 3.4 all season, except for right after Round 1, when I spiked it a little after a kids party. PH has been kept low.
So round 4 included a backwash prior to AA treatment, followed by 3 bottles (instead of 2) of Metal Magic. Pool looks fabulous right now. I'll backwash again tomorrow night. Then throw in 2 Culator pillows (double barrel). Wait another 24 hours and start gradually raising the FC.
** Any suggestions for how to keep this at bay?
One other question: My plan is to do a partial dump either at the end of this year or before opening next season. How much water would I need to pump out of my 20,000 gallon pool to be safe? I guess I will have to have fresh water trucked in, because even though my fill water is public tap water, it's really the only source I can think of for the iron. Which came out of the blue and sucker punched me, the ***.