Slamming do I adjust chlorine level with a moving CYA

[Gecrabill]

I am on day 9 of my slam.( no visible algae, just noticed the pool was using more chlorine hsn usual and the swg wasn't keeping up with the demand, oclt at regular chlorine level was 2 to 3) Prior to starting the slam, I was testing at 80/90 for cya (2 weeks prior I was at 40/50, added 45oz of granular stabilizer). So when I started the slam, I was holding the FC at 35. 4 days into the slam, I retested cya and came up around 40/50. I then for giggles, while picking up chlorine, had Leslie's test it. They came up with cya of 50, then for even more laughs, I used a test strip and it came out 35-50. I know cya can be consumed in some instances, but can this much be consumed in a matter of days? I have since brought my chlorine down to around 28 ( I know it should be 20 for Cya of 50), but I just want this slam done. I had a 1.5 fc loss Wednesday night, but then last night it went back up to 2.5 loss. Am I doing this right? FC still at 28

FYI: I am using a Tf-100
Sw florida, the pollen has been bad, but has subsided some this week.
I have a SWG

 

[JasonLion]

It is possible to lose CYA while you have algae before you start SLAMing, but that is incredibly rare.

I recommend believing the CYA test and lowering to the SLAM level for a CYA of 50.

Have you been brushing the entire pool every day?

 

[jtaves85mcss]

Please stay away from the pool store confusion and trust your own test results. The answers you need are in the Pool School link at http://www.troublefreepool.com/content/125-slam-shock-level-and-maintain-shockingl

I suggest you stop adding CYA until you are confident of your testing methods and results, along with successfully completing your SLAM. The higher your CYA is the longer it will take to resolve. No, CYA will not be used up by anything going on in your pool at this point, unless you have a very unusual bacteria conversion going on to turn it to ammonia.

Please follow the SLAM guidelines to the letter, then you will be back on track to a crystal pool that is the envy of your neighbors.

 

[Gecrabill]

Sounds good. Yes, been brushing daily. Only difference is the paver guys came out yesterday and replaced some pavers near the coping. There was some sand in the pool from the work, but I wouldn't think enough for the oclt to go backwards from the previous night. I will keep at it.