Black spots on ladder steps and green on liner

I’m not sure why I got algae bloom. My fc level was 6.5 when I got home tonight. Yesterday it was 9.0. Yesterday I read my CYA up around 90.

Does anyone think maybe it’s higher than I think. I’m very careful when I’m doing the readings but I can’t think of anything else to explain todays algae bloom???
If you had algae earlier and didn’t follow through with the SLAM process the algae is still in there growing.
 
With 90 CYA, you are likely not keeping your water above minimum, which is 7. And if your CYA is higher, you are definitely not running FC high enough.

You really want to shoot for the high number in your target range SLAM amount, or even a point or two higher. That way you don’t drop below minimum for any length of time. Let us know where your CYA lands after your partial drain and we can talk SLAM.
 
With 90 CYA, you are likely not keeping your water above minimum, which is 7. And if your CYA is higher, you are definitely not running FC high enough.

You really want to shoot for the high number in your target range SLAM amount, or even a point or two higher. That way you don’t drop below minimum for any length of time. Let us know where your CYA lands after your partial drain and we can talk SLAM.
My cya yesterday after the fill was 60 (see below-today my reading is lower - 50) and the fc was 6.5 . Please look at my pool math logs. It shows my history of test results in detail. I post nearly every day. I almost always keep the fc at the upper end of the target fc.

However as it was pointed out to me recently that about 20 days ago fc dropped to 2.7. He said that’s where my trouble began.

I started the slam last night - I added 319 oz of lc. It raised my fc to 28.5. This morning it was 26.0

I just took current readings as follows:

Fc. 22
Cc.5
CYA. 50. I believe this is a better reading than last nights 60
Temp 72

The slam target is 20 which I am a little above. I will take two more readings today and do an OCLT overnight.

Is the CYA reading affected by the higher fc level??

And the green water has gotten much less green and clearer🙂
 
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My cya yesterday after the fill was 60 (see below-today my reading is lower - 50) and the fc was 6.5 . Please look at my pool math logs. It shows my history of test results in detail. I post nearly every day. I almost always keep the fc at the upper end of the target fc.

However as it was pointed out to me recently about 20 days ago it dropped to 2.7. He said that where my trouble began.

I started the slam last night - I added 319 oz of lc. It raised my fc to 28.5. This morning it was 26.0

I just took current readings as follows:

Fc. 22
Cc.5
CYA. 50. I believe this is a better reading than last nights 60
Temp 72

The slam target is 20 which I am a little above. I will take two more readings today and do an OCLT overnight.

Is the CYA reading affected by the higher fc level??

And the green water has gotten much less green and clearer🙂
Don’t bother with any OCLT if the water is still green. Even if you pass, you still have to keep slamming until the green is gone.
 
Don’t bother with any OCLT if the water is still green. Even if you pass, you still have to keep slamming until the green is gone.
Thanks - that makes 💯 % sense! Too bad I didn’t think of that on my own.🥴

The green is disappearing pretty much - now when I look at steps and main drain they have a yellowish tint. I’m wondering if that is algae or a metal showing up in the water due to go chorine level. See attached photos
 

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How is it looking today ?
Water is back to Crystal clear. Replenished the salt to target.

Doing OCLT overnight. How long after sunrise do I have to take morning reading. Is it right after sunrise or is it until sun first directly hits the pool which could be an hour or so after sunrise?
 

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Water is back to Crystal clear. Replenished the salt to target.

Doing OCLT overnight. How long after sunrise do I have to take morning reading. Is it right after sunrise or is it until sun first directly hits the pool which could be an hour or so after sunrise?
Before sunrise! No sunlight allowed.
 
Probably doesn’t have to be technically before sunrise. It just needs to be before sunlight hits the water. The whole point of the test is to rule out any chlorine consumption caused by UV rays from the sun.
Thanks - that makes sense. I believe that the test was a pass. But to be sure I’ll redo tonight
 
Now that my slam is done I’m letting the fc drift downward. I went and had my pool tested at Leslie’s just for comparison and to see if my CYA seems close. I’m looking for advise as to how I should proceed in rebalancing - eg. Raise alk first or ph first as soon as fc gets below 10?

My readings are in pool math please see them.

Leslies are listed first in each of the following items mine using Taylor 2006 are after leslies:

1. CYA. 60. Vs me. 55
2. Ph. 7.0. vs me. 7.1 taken 4 days prior - before slam
3. Alk. 33. Vs me 60 taken 4 days ago . They state their reading was adjusted due to CYA affecting tested alkalinity?? Not sure what that means?

4. Fc. 12. vs me. 16.5. Their reading was about 4.0 lowere than my reading twice. Is the Taylor reading affected by the high readings due to slam?

5. Ch 123. Me 170. taken 4 days ago

I know TFP states pool store readings are unreliable. However they use a expensive looking electronic reading device.

I’m looking for advise as to how I should proceed in rebalancing - eg. Raise alk first or ph first as soon as fc gets below 10?
 
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Now that my slam is done I’m letting the fc drift downward. I went and had my pool tested at Leslie’s just for comparison and to see if my CYA seems close. I’m looking for advise as to how I should proceed in rebalancing - eg. Raise alk first or ph first as soon as fc gets below 10?

My readings are in pool math please see them.

Leslies are listed first in each of the following items mine using Taylor 2006 are after leslies:

1. CYA. 60. Vs me. 55
2. Ph. 7.0. vs me. 7.1 taken 4 days prior - before slam
3. Alk. 33. Vs me 60 taken 4 days ago . They state their reading was adjusted due to CYA affecting tested alkalinity?? Not sure what that means?

4. Fc. 12. vs me. 16.5. Their reading was about 4.0 lowere than my reading twice. Is the Taylor reading affected by the high readings due to slam?

5. Ch 123. Me 170. taken 4 days ago

I know TFP states pool store readings are unreliable. However they use a expensive looking electronic reading device.

I’m looking for advise as to how I should proceed in rebalancing - eg. Raise alk first or ph first as soon as fc gets below 10?
No one will even look at the Leslie’s results. They’re that bad.

You don’t need to do anything. Numbers are fine.
 
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Your actual ta of 60 is fine
(Any actual ta of 50 or above is fine)
Their “adjusted” ta is irrelevant. They want to sell you expensive baking soda that you don’t actually need because they also want to sell you other things like trichlor & dichlor which will tank your ph & ta.
Your ph is fine (if you want to raise it a little point the jets up to aerate the water & get in & splash around)
Otherwise it will rise on its own anyway.
Any ph in the 7’s is fine.
A cya of 55 counts as 60 - chlorinate accordingly FC/CYA Levels
Always round up if between two values for chlorination purposes.
For fc - The Taylor reading is not affected by high fc levels (which is why we recommend that particular test)
but their “expensive looking test equipment” is.
From here on out dose/aim for high target 🎯 for your cya (which is 9ppm) or a scootch higher so you don’t risk broaching minimum before your next dose/check due to a higher uv day/ higher bather load/ unforeseen circumstance & enjoy your trouble free pool 😊
With it being later in the season there’s no need to increase your cya to the 70’s if your swg is keeping up.
 
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No one will even look at the Leslie’s results. They’re that bad.

You don’t need to do anything. Numbers are
Your actual ta of 60 is fine
(Any actual ta of 50 or above is fine)
Their “adjusted” ta is irrelevant. They want to sell you expensive baking soda that you don’t actually need because they also want to sell you other things like trichlor & dichlor which will tank your ph & ta.
Your ph is fine (if you want to raise it a little point the jets up to aerate the water & get in & splash around)
Otherwise it will rise on its own anyway.
Any ph in the 7’s is fine.
A cya of 55 counts as 60 - chlorinate accordingly FC/CYA Levels
Always round up if between two values for chlorination purposes.
The Taylor reading is not affected by high fc levels (which is why we recommend that particular test)
but their “expensive looking test equipment” is.
From here on out dose/aim for high target 🎯 for your cya (which is 9ppm) or a scootch higher so you don’t risk broaching minimum before your next dose/check due to a higher uv day/ higher bather load/ unforeseen circumstance & enjoy your trouble free pool 😊
With it being later in the season there’s no need to increase your cya to the 70’s if your swg is keeping up.
thank you that is a great explanation in reply to my questions.
I was worried that the ph is too low and that the acidity would affect the SWG plates.

I don’t think there will be any problem for the SWG to keep up with fc since the weather here is cooling. Today without the SWG and the outside temperature of low 80’s the fc only dropped about 1 or 2 ppm by 4 pm.
 
In reply to earlier posts I replaced the ladder steps. Found the heavy algae on the back side. I’m hoping this was the cause of my problems. However I have another set of main entrance steps which I can’t see the back of . I guess that will have to be replaced next year. They probably run about $1k
 

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