Newbie, with a new pool issue encounter

Hello everyone,

Im the son of a long time pool owner with a new pool installed last year (17.2k gallons, vinyl) - it's been running well, and I've been testing regularly and managing the chlorine (free and total) alkalinity, pH, hardness (cough cough) and CYA, etc. I do this for my parents as they have better things to do with their time. But every once in a while, they chip in and help with things. (more on that in a moment)

The pool filter has a tri-chlor cartridge that holds about eight 3" rounds, which when the pool is run on cycle timer, usually disappear in about a week and a half. Shock is usually once every two weeks or more if more rain, swimming, etc, adding two pounds of granular to water, then to the pool. There havent been any issues this year or last with cloudiness, unpleasant water quality for swimming, odor, etc. All around easy. Then the roof caved in....

It was time to shock, and my Dad decided that he'd use up some of the liquid chlorine 12.5% that he had sitting around in blue 5 gal containers, that he used to dump into the old pool to shock. Well, sure enough, he adds it in to the new pool, and in no time, the plastic parts of the bottom jets, the wall pieces by the steps, the skimmers, pool steps...all have brown stains. I checked to see if Vitamin C removed it, grabbed a rite aid tablet and wiped it on. Stains came off. So....now the tricky part.

1) why did this happen? Coincidence, or did the liquid chlorine precipitate this?
2) how to get rid of the stain, and make sure it doesnt come back?

I have 2lbs of ascorbic acid at the ready, and 32oz of Metal Free. I havent used this yet, because Ive heard conflicting info on the order of events and timing. If I had to take a stab at it, I'd let the chlorine run down low, maybe close to zero but not zero, add 1lb of AA, check for stain removal, then wait a couple of hours, and add the Metal Free.

But some folks say add the metal free right after, and some people say put it in before. And supposedly the filter should be on 24.7 for this. (which makes my Dad crazy, but whatever) And after this, you shouldnt shock for two weeks (??) but instead should slowly raise the chlorine in doses?

Thoughts? I dont want to make a bad situation worse, especially since Ive read stories that I could end up with brown water or cloudy water, etc.

thanks for any help you can provide!
G

Chlorine tends to precipitate iron, especially when added in large quantities at high-ish pH. Also, industrial bleach (as opposed to laundry bleach) often had quite a bit of iron in it. It's normally chelated by adding sugar during manufacture, which creates gluconic acid, but laundry bleach is filtered to remove the iron.

Your iron could be from one or both factors.

Regarding removal, I have a complete thread in this section on that topic -- read and follow it. It covers the EXACT order in some detail. Take the Metal Free back; it's not chlorine compatible enough to work well for you.

By the way, do NOT stop chlorinating while you worry about the iron -- you don't want to deal with BOTH iron AND algae!. If you want to, you can use polyquat to allow lower chlorine levels, and you'll need some anyhow, during the no-chlorine period of clean up.

Good luck!

Thanks! I had checked the pH regularly and don't believe it was high when the liquid chlorine was added. I have no idea where this product came from, or its quality, and will have to go look at the label and see if I can get more info on what exactly it was. When I glanced at it, I noticed that it was 12.5%, and that is all I noticed.

I'm probably being obtuse, but I haven't found the thread you mentioned about removal, but would be happy to follow it exactly once I locate it. I will also happily return the Metal Free, and Im assuming your thread recommends a more appropriate product.

I have not run the chlorine down to zero as I definitely agree that I dont want to deal with algae too! Thanks for your reply!