Just Converted to BBB...now Metal Stains?

[jenandthegang]

This is my first year on BBB and I successfully turned our swamp into a sparkly oasis earlier this month thanks to you all! I've read a ton of pool school posts, and am testing the water regularly with my Taylor test kit.

In the past 3 years I've had perfectly clear but probably not safe water on the "pool store" method. My FC was always only around 1ppm. This year I switched to BBB and because of high CYA (75) at the beginning of the summer I had to shock to high levels around 30ppm to turn my swamp sparkly after opening. I lowered my CYA through partial drain/refill with well water and it's now between 50 and 60. (Grrr....I think I ended up trading high CYA for metals.)

I've noticed that light brown stains are appearing over large areas of the pool and my logical conclusion is iron because of the well water combined with high chlorine levels. I wasn't too concerned because I figured even if it was metals, I probably wouldn't need to shock very often if I followed BBB. Then a neighbor's kid pooed in my pool. Then a chipmunk died in the pool. :thumbdown: And this week a mole died in the pool. So you can see I am ending up needing to keep the chlorine up more than I wanted to and I think that's bringing out the metal stains!

I don't want to halt our swimming to do the AA treatment...but I'm distressed by the stains. Can anyone give me advice? Perhaps add Jack's sequestrant now to prevent further staining and then do the treatment in September before closing and in cooler temps? But I don't want the stains to set in....

I'd attach a picture but everyone I've tried to take hasn't successfully shown the stains. They remind me of the stains that tea bags leave on the inside of a plastic iced tea maker.

Someone help me, I'm freakin' out here!

Thanks!
Jen


Tonight's readings:
FC 4
CC .5
pH 8.0 (has been holding at 7.2...went up this week while I was on vacation)
TA 120
CYA (not sure at the moment....out of reagent which is on order from Amazon)

 

[Butterfly]

I really like the idea of starting the sequestrant and dealing w/the AA treatment at then end of pool season.

If the stains aren't too large, you could crush cheap vitamin C tabs in a sock and move it around on the stains.

 

[chem geek]

First off, lower the pH. Metal stains occur because the pH rises. It's not the high chlorine level from shocking that causes stains but rather the high pH when adding hypochlorite types of chlorine.

The stains are probably iron which fortunately are easier to treat. Follow the procedure in Metals in the Water and Metal Stains. Or as was just noted, you can wait till later in the season. Just lowering the pH will likely lighten up some of the stains.

In the future, next time you decide to shock if something happens that you feel requires a shock, lower the pH significantly first (say, to 7.2) before you add chlorine to shock the pool. That should help minimize any staining that would otherwise occur.

 

[jenandthegang]

Thanks for the replies!

I had read the long post on the AA treatment (ascorbic-treatment-to-rid-pool-of-metal-stains-t2298-20.html) and saw a comment by Jason Lion that high FC levels cause staining in addition to high pH levels, and since I've been maintaining my pH at 7.2 this season, I assumed the staining must be from the high FC levels I've created during the shock process, but maybe not.

I'll try lowering my pH back to 7.2 first and see if it lightens the stains. Then I'll try putting in a sequestrant to hold me over to the end of the summer when I'll do the AA treatment. Does anyone know if my iron stains will be more difficult to get out if I wait 2 1/2 more months before I treat them? They are not in small areas - they are over large areas of the pool. I've attached a pic. Does this help to confirm that the stains look like iron?

 

[Swampwoman]

I can't be trusted because everything looks like iron to me That is because I fight iron and am on well and have stains
Ergo, the vitamin c test is your best bet, although with well water, iron is certainly a likely suspect.

If you use a sequestrant like Jack's Magic Pink or Haviland's Proteam Metal Magic (both good imho) just be sure that you MAINTAIN it weekly -- eg. if you start out with 2 quarts, you'll need to add about 12-16 ounces a week to maintain. Otherwise, if you do have much iron, you will note things such as steps discoloring, overall light yellowing on liner etc.

Also, you may want to consider connecting your fill faucet to your water softener (provided you have one...I assume you do if on well.) Alternately or in addition, you may want to use one of those hose filters to try to keep NEW iron out.

Lastly, I do have some historic stains that I suspect are iron that have NOT responded nearly as well to Ascorbic Acid as "fresher" stains. But my pool sat swamplike for a few years in a foreclosure before we bought it, so my expectations are accordingly modest -- just happy the whole darn system works like a charm. I am learning just not to LOOK at the stains and enjoy the pool