Balancing Water After Stain/Metal Treatment

Samiamk

Member
Aug 17, 2020
6
Central NJ
I’m a chemistry newbie. We moved into a home with an approx 15,000 (I think!) vinyl kidney shaped in ground pool. The water all season has mostly been crystal blue even though Ive struggled with low ph and high chlorine levels. Although I skim daily and brush & vacuum 2-3 times a week I’ve noticed yellowish green staining on the floor that spread over time which ultimately made the water look green.

Online research suggested it was metal staining so 3 days ago I added Stain Free (citric acid) and it began to work immediately. I followed directions and let it sit overnight. The next day I added Metal Free when the water looked like blue milk. Since treatment required low ph and chlorine levels, I’m now trying to balance the water while praying the water will clear up.

Yesterday I added 5 lb ph increaser, which raised my level to 7.2 (AquaChek) but chlorine was 0. The treatment specified not to shock pool for a week so I added Dichlor tabs to skimmer basket to try to build Chlorine levels slowly.

This morning the water is still cloudy and looks like green milk. There is still 0 free chlorine and the alkalinity and cya seem high (see pics). I’ve been running the filter 24/7 since day 2.

Did I screw up somewhere along the way?Did I add chlorine too soon? Any guidance is truly appreciated. Thank you!
 

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markayash

Gold Supporter
Mar 21, 2016
2,527
Atlanta Ga
Citric acid is a chlorine neutralizer so you have to add a LOT of chlorine to get it back up. If your FC is zero I would do a SLAM or at least add a gallon or more of LIquid chlorine. Last time I did mine I bought 6 gallons in advance and added it everyday until it would hold..

I can't tell from the picture but it looks like algae.

Also please get a test kit :) Strips are plus or minus 5 on FC on good days..I have some strips I used to see if I have CHlorine. The other day I did a test and my test showed FC 7 but the strips showed 3.
 

markayash

Gold Supporter
Mar 21, 2016
2,527
Atlanta Ga
I brought my levels up slow but did use PolyQuat60 and didn't let them stay at zero more than 12 hours
I am afraid you have a big algae pond now.
I would get a good test kit and start adding liquid chlorine asap and at least try and get FC to at least stay around 7 to 10. I don't know your CYA so kind of a guess but its a start
 

DeanP66

Well-known member
Mar 26, 2014
816
San Jose, CA
A good quality test kit like the TF-100 or the Taylor K2006C is a MUST! Test strips are unreliable and don't give you the accuracy you need. We call them 'guess strips' here. It looks like you have algae, and although you're not supposed to shock your pool for a while after a stain treatment, you pretty much have no choice if you want to clear up the algae.

You may have to try the stain treatment again. I have done several in the past. I usually :

1) start with pH in the 7.2-7.4 range
2) add AA (ascorbic acid) around the perimeter of the pool, plus some in the middle
3) brush it around a little so it mixes especially around areas where the stains are bad
4) After a couple of hours, I add 2 quarts of MM (Metal Magic)
5) A couple of hours later, I start bringing the chlorine back up. I usually put in 4 to 6ppm of FC at a time.

At first the FC won't last very long at all. It will be completely gone in less than an hour. So I retest, and top it back up to 6ppm again. It will take a lot FC to neutralize all the AA or citric acid in the pool. Little by little, you'll see the FC start to hold more and more. You've got to stay on it to make sure your pool doesn't go long with 0 FC or you risk algae getting started, which is probably what happened to your pool.
 

Samiamk

Member
Aug 17, 2020
6
Central NJ
Ugg I was really hoping it wasn’t algae yet. I’m not even sure what algae looks like because I’ve never seen or felt any on the walls or floor. I’ll double shock it tonight. Thanks for your help!
 

Samiamk

Member
Aug 17, 2020
6
Central NJ
Thanks @Momma4. I’m going to read about the SLAM method because after brushing and adding a double shocking, my FC still hasn’t budged this morning. Also, I hear/read so much about backwashing but I’m afraid my cartridge filter must be really old because it has no settings to choose from.
 
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Newdude

Well-known member
Jun 16, 2019
4,512
NY
Also, I hear/read so much about backwashing but I’m afraid my cartridge filter must be really old because it has no settings to choose from.
Those are the other kinds of filters. Yours won’t have that need or option for backwashing so rest assured. :) Some cartridge filters have a waste option for draining and vacuuming but some don’t. It’s a nice option to have when you need it but doesn’t matter 9 times out of 10.