Next Steps After AA Treatment

[Jen_om]

I had my 16,500gl vinyl lined pool opened a couple weeks ago and I have no idea what they put in it but I'm guessing nothing they haven't used before. I've had all my other chlorinating systems off so far, wanted to get everything balanced before thinking about maintenance. When the pool cleared up I noticed a TON of iron stains all the way around the pool, mostly where the wall meets the floor. I tested with Vit C tablets to confirm it was iron. I let the FC drop to zero, my ph was already 7.2 so I left it there then I added two bottles of Metal Magic (just slightly more than called for based on my gallons). The MM lifted some stain but not a lot (I also backwashed and rinsed numerous times). My pool store was out of Polyquat 60 so I added two bottles of Polyquat 30. I then ordered 2lb AA online and added that. A couple days later all the stains were gone so I was ready to sequestor the stains. I had to go to a different pool store so unfortunately I couldn't get more Metal Magic or Polyquat 60 so I ended up with Metal Free instead, a bottle of Leslie's Algae Control 60% (which says it's poly) and a culator which I tossed into the filter pump.

At this point my stains are gone but my water is super cloudy. I thought I was ready to start bringing the FC back up so I just went out did all the tests to figure out what I need to get. Results:
FC: 0
Alk: 80
ph: 6.8
Hardness: 300

Before I make some grave error, my plan for tomorrow is to bring my alkalinity down, raise my ph and start slowly adding liquid chlorine. I'll pick up some more sequestrant in case I see stains come back, and I'll keep regularly backwashing in hopes of getting rid of some of the sequestered iron.

What am I missing? It takes me an hour roundtrip to the pool store so tell me what I need to have on hand or that I am getting wrong or forgetting!

 

[DeanP66]

You can get the Metal Magic from Amazon (4 bottles for $62). You'll need some for monthly maintenance doses. I use half a bottle monthly in my 20,000 gallon plaster pool.

You don't need to lower TA, but your pH does have to rise. Use Borax to raise it to 7.2ish. The cloudiness could be from the MM if you used too much or it could be from something starting to grow in the water. Do you know what your CYA level is? I'm asking because if it's high, you could kill two birds with one stone and drain the water (once you are happy with the stains being gone) and refill with fresh water. That will eliminate the metals from the water (or most of them because you should leave at least 1 foot of water in a vinyl pool to protect the liner.

 

[Jen_om]

I didn't test it tonight but last time I tested at the pool store my CYA was 90. I had astronomically high CYA last year after I repeatedly used chlorine free shock which contained CYA. I let a lot of water out of the pool when I opened it and added new water (not well) and that brought it down to the 90 level.

I can't do a refill. It's really not easy where we live (rural). Is it a complete waste of time to backwash and use the culator? Adding monthly sequestrant is obviously less than ideal.

 

[DeanP66]

The AA and MM sequesterant lift the stains, but they stay in the water. The CULator is supposed to catch some of them but reviews have been mixed. I got one myself and tried it and the little bag never turned a different color at all. So, a monthly dose of sequesterant will probably only cost you around $8 a month (half a bottle). That's not too much IMO. I've been using it since last August and it seems to work fine.

Here's where I was at last August and after I did the treatment:

 

[Jen_om]

Here's where I'm at...

After adding 2.5gl of liquid chlorine my FC was still 0 and water still cloudy. The water also turned green every time I added some of the chlorine. I was adding slowly so as not to put stains back down on the liner. I've now added a total of 3.75gl of liquid chlorine over the course of 3 days. I haven't tested my FC yet this morning, waiting for the water to circulate a bit this morning. I did have the water tested at two pool stores over the past few days and they both reported my alkalinity was in the low 40s so I added about 15lbs of alkalinity up. I have another 1.25gl of liquid chlorine to add today before I test again. I'll also Taylor test everything again today to see how it compares.

The water turning green every time I add chlorine bothers me. The pool store said that's an algae bloom but reading here suggests it's actually the iron showing up again. It only lasts a couple minutes then goes back to blue. I have the culator in the pump but it hasn't changed color. Aside from draining and refilling the pool I'm not sure what to do about that.

I have left my ph alone and it's raised slightly to 7/7.1 over the past couple tests I've done. No one is swimming in this yet though.

Any more advice?

 

[DeanP66]

Don't be alarmed that your FC is showing 0. It is working against the AA in the pool to neutralize it. It took me nearly 4 days before my FC started holding. I would put in around 6 PPM at a time and it was gone literally 2 hours later. I kept adding and adding, almost like I was doing a SLAM, but I stuck with keeping the FC additions around 6 PPM per dose. I went through nearly 10 gallons of chlorine before the FC started to hold with any regularity. I used 6 LBs of AA though so, it may not take you as long. Just be vigilant about testing and topping it back up to 6 as often as you can.

If the water turns back right away like you said, I wouldn't worry about it. I notice some discoloration when I add liquid chlorine to my pool especially when the sun is in full force. It disappears within minutes though. Leave your pH and TA alone until after you're finished stabilizing your FC. I didn't notice you specify what kind of test kit you have. Hopefully, it's one of the two we recommend on this site. Either the TF-100 or the Taylor K2006C. Trust your own tests, and stay out of the pool store, or at least don't let them test your water. It has been shown over and over again that pool store testing can't be trusted.

Just keep doing what you're doing and you'll turn the corner soon when the FC starts holding. How about a picture or two of your pool?

 

[Jen_om]

I use the Taylor K2006. I just went out and tested again and then added more chlorine, now up to 5gl since I started this process. Picture below of before I added the chlorine then right after I added it. The water is blue again within 5 minutes, but still cloudy.

My results before I added today's chlorine:
FC: 0
Ph: 7
Alk: 130
CYA: approx 90 (below the 100 line on the test tube)

 

[DeanP66]

Does it return to that original blue state after adding the chlorine? I'm wondering if that Pool Frog Mineralizer might have something to do with it? Do you use it? Copper is not something you want in your pool. That's another possibility. Those mineral systems are generally bad news and can cause side effects. Hopefully somebody more knowledgeable that me will chime in with some more info.

Is your pump running 24/7 right now? It should be in order to clear the pool of the cloudiness. With your CYA at 90, you might try bumping that FC up to 10 PPM just in case there is something in that water. It should shorten the time it takes for the FC to start holding as well.

 

[Jen_om]

Yes! The water is back to that blue state in less than 5 minutes, cloudly water but blue. I took the blue pic today right before I put in more chlorine then I took the green pics. It's blue again now. I have not turned on the Pool Frog this year. I intentionally kept it off when I opened the pool until I could deal with the stains. I emailed the Pool Frog people and they told me there is no iron in the mineralizer. Unless copper reacts the same way to vitamin C/AA then my stains were definitely iron. The stains are totally gone, just dealing with the cloudiness and trying to get the FC to hold. I do have a heater so copper could be getting from there but again, these stains looked and acted like iron.

 

[DeanP66]

Your heater shouldn't be an issue unless you let the pH get really low. I assume you closed your pool during the wintertime right? A pH below 6.8 for long periods of time can corrode the heat exchanger in the heater. Hope that wasn't the case.

 

[Jen_om]

Yes, we close it in winter.