Black stains just keep getting worse

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Rich G said:
did those values change? I have this in my notes that I keep with my test kit.. I could swore I originally got it from this site (See the picture).

also, ive been playing a bunch this morning, even gone as far as pouring straight acid and chlorine on this spot and nothing.

as far as trending, no I didn’t keep a log but I tried to keep the levels within what’s listed on that paper. Obviously there were times when the chlorine would go higher or lower as I needed to adjust my SWG but those were my targets.
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The values haven’t changed much in the 3 years I’ve been around. When was that paper printed?

Realistically, a pool can use up to 4ppm of chlorine each day in the heat of summer, so keeping it at anything less than 4 is asking for trouble, though with a SWCG, it’s somewhat minimized as long as you stay on top of water testing. Are you testing the chlorine each day as recommended by TFP?

I’d recommend keeping a log of water tests either through the PoolMath app ($7/year?) or just a note on your phone. It makes troubleshooting so much easier.
 
Bperry said:
The values haven’t changed much in the 3 years I’ve been around. When was that paper printed?

Realistically, a pool can use up to 4ppm of chlorine each day in the heat of summer, so keeping it at anything less than 4 is asking for trouble, though with a SWCG, it’s somewhat minimized as long as you stay on top of water testing. Are you testing the chlorine each day as recommended by TFP?

I’d recommend keeping a log of water tests either through the PoolMath app ($7/year?) or just a note on your phone. It makes troubleshooting so much easier.
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I see. There is a second tab which basically aligns with my paper (at least for SWG)
 

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Rich G said:
I see. There is a second tab which basically aligns with my paper (at least for SWG)
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Note that the “4” on that is the minimum. It can’t be allowed to get lower than 4. And these are only advised if you are testing consistently and making sure it doesn’t go below minimum.

I think I’d try just running at the high end of that chart for a few months and see how it goes. I wouldn’t dump any more acid on it though. The Poolmath app also makes it super easy to keep track of test results and makes it easy to spot trends that bring bad news.
 
Bperry said:
Note that the “4” on that is the minimum. It can’t be allowed to get lower than 4. And these are only advised if you are testing consistently and making sure it doesn’t go below minimum.

I think I’d try just running at the high end of that chart for a few months and see how it goes. I wouldn’t dump any more acid on it though. The Poolmath app also makes it super easy to keep track of test results and makes it easy to spot trends that bring bad news.
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So I just had a guy that owns a commercial pool company and his buddy who installs the plaster for a living and they both immediately said with 100% confidence that they are organic stains.

They recommended letting chlorine just sit on the stain and keep reapplying for several days. I just poured chlorine over a couple of the stains and will see how it looks in the morning. They both said it’s better to be done in the blazing heat but I was excited to try it.

on a side note, they said for the stains near the deep end that I should drain the pool and do the same soak treatment. Obviously draining the pool scares me given the horror stories of pools popping out of the ground but they felt my pool is high enough given how low the water is in the canal next to my house.

I am wondering if I could get the same effect with just a really high chlorine level.
 
Rich G said:
So I just had a guy that owns a commercial pool company and his buddy who installs the plaster for a living and they both immediately said with 100% confidence that they are organic stains.

They recommended letting chlorine just sit on the stain and keep reapplying for several days. I just poured chlorine over a couple of the stains and will see how it looks in the morning. They both said it’s better to be done in the blazing heat but I was excited to try it.

on a side note, they said for the stains near the deep end that I should drain the pool and do the same soak treatment. Obviously draining the pool scares me given the horror stories of pools popping out of the ground but they felt my pool is high enough given how low the water is in the canal next to my house.

I am wondering if I could get the same effect with just a really high chlorine level.
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You run the risk of damaging things if you run the chlorine higher than SLAM level. I wouldn’t bother draining until you’ve tried just maintaining adequate or slightly raised chlorine level for a while.
 
Well.. it definitely seems to be working.

I have also downloaded the app and will use that for tracking. That’s good advice. I will also maintain my chlorine much higher than I was.

That said, I am at an impasse now. I ran my numbers this morning
FC 46
PH > 8
TA 120

I added acid to bring my PH down to 7.2 and opened up my aerator to bring the PH Up after lowering the TA. However obviously my chlorine is very high, and I still have stains on the bottom (can’t really see them from how cloudy the water is).

I see three possibilities now. I am leaning towards option 2 but I also don’t want to tear anything up due to such high FC

1) drain completely to attack those stains at the bottom
2) leave the pool the way it is (semi drained and high FC) and let it circulate for a week or so while the FC naturally drops and see how the stains at the bottom come out
3) fill the pool to dilute the Fc and hope the stains will eventually work themselves out over time

thanks so much for all the advice. Never realized just how bad those stains could be
 

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Rich G said:
Well.. it definitely seems to be working.

I have also downloaded the app and will use that for tracking. That’s good advice. I will also maintain my chlorine much higher than I was.

That said, I am at an impasse now. I ran my numbers this morning
FC 46
PH > 8
TA 120

I added acid to bring my PH down to 7.2 and opened up my aerator to bring the PH Up after lowering the TA. However obviously my chlorine is very high, and I still have stains on the bottom (can’t really see them from how cloudy the water is).

I see three possibilities now. I am leaning towards option 2 but I also don’t want to tear anything up due to such high FC

1) drain completely to attack those stains at the bottom
2) leave the pool the way it is (semi drained and high FC) and let it circulate for a week or so while the FC naturally drops and see how the stains at the bottom come out
3) fill the pool to dilute the Fc and hope the stains will eventually work themselves out over time

thanks so much for all the advice. Never realized just how bad those stains could be
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A couple comments:
1. FC=46? You are not following the SLAM process guide and are risking damage to the pool and equipment.

2. The pH test it totally invalid at that FC level so don’t add any acid based on that. Same warning about damage to pool and equipment because of low pH.

Follow the TFP SLAM advice to the letter.
www.troublefreepool.com

SLAM - Shock Level and Maintain

We’ve all had to deal with a green pool. Clear algae from your pool with a SLAM! Read here to use shock level and maintain to clear your pool.
www.troublefreepool.com www.troublefreepool.com
 
Bperry said:
A couple comments:
1. FC=46? You are not following the SLAM process guide and are risking damage to the pool and equipment.

2. The pH test it totally invalid at that FC level so don’t add any acid based on that. Same warning about damage to pool and equipment because of low pH.

Follow the TFP SLAM advice to the letter.
www.troublefreepool.com

SLAM - Shock Level and Maintain

We’ve all had to deal with a green pool. Clear algae from your pool with a SLAM! Read here to use shock level and maintain to clear your pool.
www.troublefreepool.com www.troublefreepool.com
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The FC got so high because I poured direct chlorine on the stains and obviously all ran into the pool.. plus the water level is lower so it just made it worse.
 

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Rich G said:
The FC got so high because I poured direct chlorine on the stains and obviously all ran into the pool.. plus the water level is lower so it just made it worse.
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Forgot to say #2 is your best option now. Don’t even test pH when the FC is over 10ppm cause it’ll be wrong.
 
Rich G said:
Thank you for so much advice. I really appreciate it.
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I might also do #3 seeing how low you drained it. I’d personally fill it (unless the frigid weather is affecting you down there) and go with the SLAM process. Once it passes (except for the stains), then I’d ride it for a while at the high end of FC for your CYA level (which will change once you fill it back up.)
 
So bad news… the stains are coming back.

I have been brushing daily, and have kept the chlorine above 9FC and most of the time it was much higher.

it seems to be the same pattern….. it’s not random
 

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  • Wow
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So I am at a complete loss now… acid does nothing to these stains and chlorine takes them away but they slowly come back In all the same places.

Since the end of December I have maintained my chems as follows
FC 8-13
PH 7.4-7.8
TA 80-100
CH 500-550
CYA 80-90

my most recent log this morning was
FC 13.0
PH 7.8
TA 100
CH 500
CYA 90

i will say that I have been slowly bringing down the FC because I put a new SWG in but I gave it some liquid before I went on a cruise for a week.

At this point I feel like my only option is refinishing the plaster
 
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It really does look like Black Algae (or black pebbles in the finish), but the OP says he cannot pick at the spots. I have never seen any BA that is not soft and easily removed with a some form of implement.

Anyone have any ideas?
 
Katodude said:
It really does look like Black Algae (or black pebbles in the finish), but the OP says he cannot pick at the spots. I have never seen any BA that is not soft and easily removed with a some form of implement.

Anyone have any ideas?
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Thanks.. I am pretty positive it’s not algae…it doesn’t really look like all the pictures I see online and I can’t pick at It with a brush, a pick, a knife, nothing. it just slowly gets darker over time. It’s the exact same pattern over and over.
 
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