July and have yet to swim!


Gold Supporter
TFP Guide
Jun 8, 2019
Milwaukee, WI
Crud, no wonder there hasn't been any improvement.
Low CYA would explain a rapid drop off of FC. But if you keep the FC up by testing and adding often, too low of CYA wouldn’t stop it from killing algae too.

Higher CYA will let more of it go to organics instead of UV though. Just test often and keep adding back to 12. :)
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Well-known member
May 29, 2019
I would say take the vacuum out. You need to brush a lot. You want to break up all of the algae so the chlorine can kill it. When I opened my pool this spring it was a swamp. I was brushing twice a day.


Mod Squad
LifeTime Supporter
Jul 10, 2012
Tallahassee, FL
Depending on the cost of your water it may be cheaper to drain some of the water. You do NOT want to drain all of it. You would need to leave about a foot to keep the liner from moving. I will let you do the cost comparison-bleach vs water.

The bleach WILL clear it over time. The more you test it and bring the FC level up to SLAM level the faster it will clear. If you work during the day it can still work.............test in the morning, test when you get home, test at dinner time, test before bed. That is 4 times with brushing thrown in at least once.

You go this!!
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Active member
Jun 7, 2019
Chicago Area
This is where I'm at currently. FC has been checked every 1 to 2 hours since I last posted (with the exception of overnight of course) and being brought back to 12. I'm averaging a drop to about 9 during that time. CYA is at 35. PH is at 7.8.
My pressure was lacking so I cleaned off the filter, picture attached. Why is it so green still? I've also attached pictures of the pool water looking straight down. I think it's a lighter green... maybe?
There shouldn't be anything for the algae to hide in; stairs are out, I'm vacuum brushing and then removing it.



Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
Laughlin, NV
Your CYA is 40 (round up). Your SLAM level FC is 16 ppm at that CYA.

As you tested your pH with FC below 10 ppm, you can add acid to lower the pH to 7.2. You need the TA data for that.


Active member
Jun 7, 2019
Chicago Area
Thank you everyone! I'm relieved to hear it should be at 16 because maybe now I'll see quicker results.
I'm going to check all my levels including TA now, get my PH down and chlorine up and hopefully see a difference soon.
Thanks again. I'll be back with pictures.
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Gold Supporter
Jul 30, 2018
Fort Mill, SC
This thread is the ultimate example of what makes TFP so great. Moderators are checking in giving advice people are being so encouraging and you have a green swamp pool turning into a crystal clear blue oasis.

Simply awesome. Thanks TFP and best of luck finishing your SLAM I will be watching this one closely.