Losing CYA

[BillB]

FC- 6.0
CC- 0
pH - 7.2
TA - 80
CH - 850
CYA - 30

I know for a fact I'm losing CYA. It was 50 ppm two months ago and it's 30 now.
There is no leakage. No splashing to amount to anything. Only my wife and I use the pool and we're too old to cause any splashing.
The only water loss is when I clean my cartridge filters.
When I started BBB I had 0 CYA. That was September of 2013.
Since then I have added 7 lb of HTH Stabalizer and conditioner (granule).
I ran my pool through the Winter.

 

[yardoasis]

I have the same problem, which I posted a thread about.

Do you have auto-fill? Or do you have to keep refilling your pool after significant evaporation loss (I see you live in TX, it's been hot lately). You've also had a lot of rain in the past 2 months?

In my case, I've had a lot of splash out, refilling once a week and letting it overflow a bit each time, and we've also had a lot of rain in June through mid July. Plus, the heat and sun warms the water to cause 2-4 ppm loss per month.

Each one of these factors, in isolation, may cause very small CYA losses, not enough to matter. However, a combination of all these factors, happening simultaneously, may cause significant CYA losses. That's my best guess.

 

[BillB]

I manually refill the pool. Under this Sun I add about 1/4"- 1/2" a day.
I've done a bucket test and am satisfied I don't have a leak.
I didn't know that warm water caused 2-4 ppm CYA loss per month.
I guess I'll go add another 2 lbs.
Thanks for the reply

Any rain we've had has long since evaporated out of the pool. I never had enough rain that I had to drain any of it out.

 

[yardoasis]

So you're adding 1/4 to 1/2 a day, for 60 days that's about 15 to 30 inches of refilled water. You might have an overflow drain (like I do) so this amount of refilling might have been diluting your CYA.