Shouldn't my CYA be going down?

[mixin16]

Hello all! First I want to say thanks! My last year with my pool was my first and it was very frustrating. This year, I am doing TFP methods and it is AWESOME! I finally can figure out what's going on with my pool, and am greatly enjoying the peace of mind that goes along with it.


Likely due to all the Biogard Smart Sticks the pool store had me on last year, my CYA is around 70ppm after opening my pool ~3 weeks ago. I would like to decrease it to ~50ppm, but am not getting it to budge. I vacuum my pool every week and at least three times, I have vacuumed it to waste to bring the water level down 5-6" and then refilled with the hose. I was hoping these water exchanges would help bring the CYA down, but it seems stuck at 70ppm. Am I just not removing enough water? To save money on my water bill, would I be better served to just wait it out and let it go down over time? (I'm ok with keeping my FC higher with the 70ppm CYA if that's the best choice).

Thanks again so much, I love this site and the pool math calculator that I use on my phone pool side!


Mike

 

[atttech-2]

A few inches at a time will reduce it but it is a long slow process. If the water is clear and you have your FC under control at a level appropriate for 70 ppm CYA I would just ride it out. As long as you don't end up needing to SLAM this summer it will be no problem at all.

 

[domct203]

To lower CYA from 70ppm to 50ppm would require a 30% drain/refill. If your average depth is 4 feet, that is just over a foot deep (14-1/2").

Three or four 6" drains should get you there, but will use more water than one 14" drain.

 

[mixin16]

Thank you very much for your responses and information!