Normal FC, no CC - Randomly Algae

bradthebold

Active member
Apr 20, 2020
38
Spokane, WA
This is my first year with the pool, but I have kept up with chlorine. Opened the pool today to add chlorine to be surprised by cloudy green water. I just tested and got FC-5, CC-0. CYA is 40, pH 7.8. Is there anyway I could get algae with my FC never dropping below minimum? I'm guessing I have to SLAM either way, but it doesn't make sense.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Is there anyway I could get algae with my FC never dropping below minimum?
I'd have to say yes. While each pool scenario is a bit different, poor water circulation could result in stagnant areas. Lack of brushing could allow biofils to increase. Keeping the water covered prevents CCs from getting oxidized as well, so that could complicate matters as well. In the end though, if you see algae, a SLAM Process is the route to go. Best to knock it out once and for all before fall gets here.
 

bradthebold

Active member
Apr 20, 2020
38
Spokane, WA
I'd have to say yes. While each pool scenario is a bit different, poor water circulation could result in stagnant areas. Lack of brushing could allow biofils to increase. Keeping the water covered prevents CCs from getting oxidized as well, so that could complicate matters as well. In the end though, if you see algae, a SLAM Process is the route to go. Best to knock it out once and for all before fall gets here.
I do leave a solar cover on most weekdays. Maybe that is the issue, affecting circulation and CC oxidation. I run my pump 10 hours/day currently. Should I open the pool every other day at least, or something like that?

I brush what the robot can't reach and let it vacuum 1-2 times a week. With the cover being on most the time, it has stayed pretty clean.

Currently SLAMing away.
 
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bradthebold

Active member
Apr 20, 2020
38
Spokane, WA
I have more things that don't make sense. This is algae right? I added chlorine to SLAM level at 5pm last night and was prepared to add every hour. At 6pm, it was a little higher than calculated, at 7pm, it was even higher than that. I tested at 10:30pm and it went down 3ppm to 18. I just tested this morning at 7AM and got FC-17.5, CC-0. Is the 10mL test inaccurate at high FC levels? Otherwise it doesn't seem like the chlorine is killing any algae.

The stain in the pics is normal, there doesn't appear to be any dead algae buildup on anything though, you can see the steps look normal. Brushing today didn't seem to remove anything or stir anything up.




 
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proavia

LifeTime Supporter
TFP Guide
Feb 6, 2015
1,969
Chandler AZ
The water looks cloudy green.
Post a full set of current test results.

FC
CC
pH
TA
CH
CYA

When you add chlorine, test about 30 minutes later. If you later test and get a higher number, either you have poor circulation or testing error. You don't say what those exact FC numbers are. Are you running the pump during and after adding FC? Are you pulling the water sample for the same location?
 
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bradthebold

Active member
Apr 20, 2020
38
Spokane, WA
The water looks cloudy green.
Post a full set of current test results.

FC
CC
pH
TA
CH
CYA
I did a full test 7/27 after adjusting everything, but can redo if needed.

FC-17.5 from this morning
CC-0 from this morning
pH-7.2 by calculation after measuring 7.8 yesterday
TA - 90 (7/27) a little lower with new acid addition
CH - 450 (7/27)
CYA - 40 (7/27)
 

proavia

LifeTime Supporter
TFP Guide
Feb 6, 2015
1,969
Chandler AZ
Continue with the SLAM Process. Your FC level for CYA 40 is 16 FC during the SLAM Process.

Brush the pool at least daily. Check the steps, light, skimmer weir and any other p,aces algae may hide - clean all those out.

The pH test reads falsely high with FC over 10. Do not adjust it during the SLAM Process

Check and dose chlorine at least 3-4 times daily to stay as close to SLAM FC level. Have patience, this isn't a one day process. Check filter pressure and backwash when pressure rises 25% above clean pressure.

Can you post a pic looking directly at the bottom drain? The water looks cloudy in your pics, but I can see the stains you mentioned.
 

bradthebold

Active member
Apr 20, 2020
38
Spokane, WA
Continue with the SLAM Process. Your FC level for CYA 40 is 16 FC during the SLAM Process.

Brush the pool at least daily. Check the steps, light, skimmer weir and any other p,aces algae may hide - clean all those out.

The pH test reads falsely high with FC over 10. Do not adjust it during the SLAM Process

Check and dose chlorine at least 3-4 times daily to stay as close to SLAM FC level. Have patience, this isn't a one day process. Check filter pressure and backwash when pressure rises 25% above clean pressure.

Can you post a pic looking directly at the bottom drain? The water looks cloudy in your pics, but I can see the stains you mentioned.

I just vacuumed after a week and it looks completely normal. Some leaves and dirt. Checked FC again 3 hours lately, still 17.5, so in 12 hours it's only gone down 0.5.

Here's a pic of the area where the main drain is, I can't see it at all though. 2 days ago you could see the screws.

 

bradthebold

Active member
Apr 20, 2020
38
Spokane, WA
How often have you been dosing and testing the water? At *least* 3-4x per day? More often is better.

Maddie
I tested yesterday at 5pm when I noticed it was green and dosed to 18ppm, then 6ppm it was really 19.5, then 7pm it was 21, then 10:30pm it was 18, then today at 7:30am it was 17.5, then 10:30am it was 17.5. I have not added since 5pm yesterday because the FC has not dropped below the SLAM value.
 

bradthebold

Active member
Apr 20, 2020
38
Spokane, WA
That just looks like a solid wall of green! Your pump is running right?? Filter pressure rising?

Have you tested for metals?? Just wondering.....?
Pump is running 24/7 at 1500rpm. Filter pressure has gone up 1-1.5psi. I tested for a lot of things and there isn't much. Iron is 0.02, which is way under 0.3ppm that should cause issues. And it went from fine to this overnight. I can see the bottom on the shallow end (3.5'), but can't see the 8' side.

I did end up adding 1.3 gal of 10% chlorine today.
 
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