Help - black agae or copper stains

SABUCKETDAD

Member
Jun 19, 2020
17
Texas
Hello everyone. I hope you can give me some ideas on what to do next. I have been battling what I believe is black algae as it somewhat comes off when I scrub it (green particles come off) but a black stain is left. I have rubbed chlorine pucks on these stains and they don't seem to want to go away. I though perhaps these were copper stains do to the fact I used a copper solar ionizer for a couple years but don't anymore. I have not tested for copper and not sure exactly how to do it but since I can get some green particles to come off it has to be algae. I also tried the vitamin c test and that did nothing.

My pool is 10,000 gallons and I started using primarily liquid chlorine and sometimes bleach.
Below are my numbers:
FC 20 *probably tested to soon after adding chlorine
CC = 0
CH = 400
TA = 40
CYA = 30 *This number was way high about a year ago and now seems too low
CL =6.7
PH= 6.8 I know this one is too low and needs to be raised

I have some pucks and thinking about using them to bring up CYA a bit.
Thinking about draining about half way and scrubbing with bleach to see if that works. Any help on these stains and recommendations is appreciated.

My pool is about 10,000 gallons and I useIMG_9316.jpgIMG_9315 (1).jpg
 

Texas Splash

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How old is this pool/plaster? Do you have some dry acid handy? If so, put some in a thin sock or nylon and try rubbing that on the stain. If it works - copper. If it does nothing, it could be the BA roots have imbedded so far the puck can't get to it. Definitely get teh TA and pH up ASAP as that is very corrosive.
 
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SABUCKETDAD

Member
Jun 19, 2020
17
Texas
How old is this pool/plaster? Do you have some dry acid handy? If so, put some in a thin sock or nylon and try rubbing that on the stain. If it works - copper. If it does nothing, it could be the BA roots have imbedded so far the puck can't get to it. Definitely get teh TA and pH up ASAP as that is very corrosive.
The pool is roughly 10 years old. I don't have any dry acid but can definitely get some. Can you suggest a particular brand and place to buy? I have never used it before.
Will also get the TA and PH up right away.

Thank you!
 

SABUCKETDAD

Member
Jun 19, 2020
17
Texas
You can probably get some at Walmart under the name pH Down. I'm sure the pool store has some at their cost as well.
Thank you and sorry for the delay. We have had crazy storms over the weekend and pool took a beating with overflow and inflow of mulch, dirt, etc. All my neighbors battling it as well.

Will give it a try and probably alot more out of wack now. Almost back to clear now.

Thanks and will report back.
 
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kellyfair

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Jun 29, 2016
4,767
Tampa, FL
Pool Size
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Intex Krystal Clear
Is your water really that green, or is photo exaggerating?

Also, your FC is quite high, even if you are trying to SLAM. Did you add while pump is running, and near a return? How soon after adding did you test, and where did you pull your sample?
 

SABUCKETDAD

Member
Jun 19, 2020
17
Texas
Is your water really that green, or is photo exaggerating?

Also, your FC is quite high, even if you are trying to SLAM. Did you add while pump is running, and near a return? How soon after adding did you test, and where did you pull your sample?
The water is crystal clear so must be the photo. No green water fortunately. I did test way to soon after I added liquid chlorine so that is the reason it is so high.

I have had to take a few days to get it clear again from the recent storms and overflow into my pool of dirt. Water was brown a few days ago.

So now finally back to where I was and will be getting the PH down today to confirm algae and not copper.

Thank you for the reply!
 

kellyfair

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Jun 29, 2016
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Tampa, FL
Pool Size
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Intex Krystal Clear
I did test way to soon after I added liquid chlorine so that is the reason it is so high.
No, if you are adding chlorine in the correct amount and adding it in front of return with pump on, unless you are immediately taking sample right at same spot, it shouldn’t be higher than you intended. How long after you added did you do the test?
 

SABUCKETDAD

Member
Jun 19, 2020
17
Texas
No, if you are adding chlorine in the correct amount and adding it in front of return with pump on, unless you are immediately taking sample right at same spot, it shouldn’t be higher than you intended. How long after you added did you do the test?
Sorry for the delay again. Had more crazy storms and heavy rain and another day of overflow into the pool which I am still clearing to get back to normal. I have a drainage issue that needs to be resolved this summer.

I typically add the chlorine under the waterfalls so that it gets disperesed quickly. Do you recommend in front of the skimmer basket returns?
 

kellyfair

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Jun 29, 2016
4,767
Tampa, FL
Pool Size
7000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Intex Krystal Clear
Sorry for the delay again. Had more crazy storms and heavy rain and another day of overflow into the pool which I am still clearing to get back to normal. I have a drainage issue that needs to be resolved this summer.

I typically add the chlorine under the waterfalls so that it gets disperesed quickly. Do you recommend in front of the skimmer basket returns?
Wherever it is going to be diluted and dispersed is fine. You can test within a few minutes, and you should not be seeing crazy high numbers. If you are, then you need to re-check your Pool Math to make sure you are correct in your pool volume and other calculations.
 
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SABUCKETDAD

Member
Jun 19, 2020
17
Texas
Wherever it is going to be diluted and dispersed is fine. You can test within a few minutes, and you should not be seeing crazy high numbers. If you are, then you need to re-check your Pool Math to make sure you are correct in your pool volume and other calculations.
I likely made a mistake with the math. Once it get it clear again I will run through all the tests again and see where I am.

Thanks!
 
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SABUCKETDAD

Member
Jun 19, 2020
17
Texas
Ok. Quick update as my pool is finally back to clear water and all my numbers are in line. Confirmed that I am not dealing with copper and it is black mold.

I can scrub areas and even hit them with liquid chlorine as they are heaviest just below the water line so pouring it right there hits the mold hard and you can visibly see it lighten up immediately. However the stain is still there.

My pool is only 10K so I have decided the quickest and likely least costly way to get this taken care of is to drain it. That is my plan for this weekend. I could keep trying to battle this without the drain but my family doesn't want to invite friends over until it is gone which I understand.

With that said, any suggestions on what to use once it is empty? I would prefer not to use an acid and thinking a liquid chlorine bath and brush should likely do it.

Any thoughts or suggestions would be hugely appreciated!

Also, my pool is Pebble-Tech or a brand similar.

Thank you.
 

SABUCKETDAD

Member
Jun 19, 2020
17
Texas
We are North of Dallas (Frisco/Plano) area and have had plenty of rain for sure. While the majority of it would only require a foot of water or so (pool is roughly 4 feet deep) my fear is that without a complete drain there would be no way to get it all. I would rather have that fear of course than a pop-out.

Thoughts on the max amount of water you think would be safe? And I will put in writing here that I won't hold anyone liable for recommended amounts....:LOL:
 
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