CYA strategy for smaller SWG pool with frequent 2" downpours of rain

[Newpoolcrazy]

First off, we need to buy new stabilizer because we bought Clorox and it doesn't do a thing. Read about Protech on another thread but not sure which pool stores sell it. We only have Leslie's nearby, but will travel.

Had CYA at a nice level just under 80, then here comes the rain. We've had to drain 2-3 inches a couple times in the last 3 days and will have to again tonight. How do I handle my FC levels if I don't know what my CYA is? How long after adding a GOOD stabilizer should my reading be correct? We are getting these downpours every 2-3 days so water replacement is happening a lot. I have been keeping my FC on the high side as if CYA were 70-80, but with a TA of 70 my Ph is drifting up, so I assume I'm over chlorinating.

Any advice on handling this better than I have been?

Readings last night were

FC 8
CC 0
Ph 7.7
TA 70
CYA God only knows, but I'm treating it like it's 70

And yes it's raining again.

 

[Modawg2k]

I use the HTH brand at walmart, and my CYA always rises in accordance to what poolmath says it will. If that stabilizer is in powder form, I believe they say to give it a week before measuring.

 

[atttech-2]

In round numbers 3" drain is 6% of your water volume, if you start with a CYA level of 80 you would be 4.8 ppm lower after each 3" drain so call it 5. I would just adjust your CYA down by 10ppm after every 6" of water drain, and once you think you have drained a total of 12" retest the CYA adjust it back up to 80 and start the process again. Keeping the FC a bit on the high side as you have been is a good idea while dealing with the rain I would rather deal with that than have to go through a slam.

FYI 36 hrs after it dissolves should be enough to get a good reading, of course you can always wait longer if you want to be 100% sure

 

[Newpoolcrazy]

Thanks so much! I was looking for a way to estimate CYA during these times. At least it helps to give me an idea. And 36 hours should at least help see if it's working (like Clorox brand doesn't). Thanks again. It's just what I needed.

In round numbers 3" drain is 6% of your water volume, if you start with a CYA level of 80 you would be 4.8 ppm lower after each 3" drain so call it 5. I would just adjust your CYA down by 10ppm after every 6" of water drain, and once you think you have drained a total of 12" retest the CYA adjust it back up to 80 and start the process again. Keeping the FC a bit on the high side as you have been is a good idea while dealing with the rain I would rather deal with that than have to go through a slam.

FYI 36 hrs after it dissolves should be enough to get a good reading, of course you can always wait longer if you want to be 100% sure