Adjust CYA or SLAM first?

[Nate4429]

Crud!!!!! Algae again Had it all clear with a successful SLAM almost 2 months ago and now its back bigger a badder than before. Only good thing is that our swim season is over here in the Pacific NW without a heater. I've been on top of my levels everyday since the last SLAM so I'm not sure how this happened this time. My last full level check my CYA ticked up to 60 which is over my 30-50 range. So my question is do I drain 1/2 my pool and refill to hopefully drop my CYA or do a SLAM first then adjust my CYA?

 

[ajw22]

You can do the SLAM Process at CYA 60. It will just take twice as much chlorine as CYA 30. If you intend to lower your CYA anyway then you might as well lower CYA then SLAM.

 

[Nate4429]

Thanks I started the SLAM process tonight. I do want to lower my CYA numbers before next season. We are on a well and are starting to get lots of rain and have a really deep and good well but this is the time of the year I think would be best for us to drain 1/2 the pool to adjust the CYA before putting it to bed for the winter. But I think I'm going to lean towards getting the SLAM done first and then adjusting unless that's just a terrible idea...Any thoughts?

 

[wireform]

I think you should slam the way it is. Over the winter the CYA will diminish with the snow and rain that you will pump off the cover. You'll will also lose water when winter prep to bring the level below the jets.