CYA gone???

[Dkoucky]

I just got a solar cover this year and I might be crazy but I think it is creating something that is breaking down my CYA.

2x this year my pool has gone from stable to green. No need to preach as I have learned my lesson but I get in a habit of testing only FC and PH when things are going well. We have not been swimming much the past month and I have just left the solar cover on. All went well for 3 weeks, this past week I had some algae settling on the bottom an my FC dropped to 1 ppm. I added bleach to bring it back to 5 and ran the robot.

That angered the pool gods and now I am at 0 FC and all of my CYA has disappeared. This happened to me once earlier in the year as well.

Is it possible the solar cover is causing a problem? I can't imagine a reason for CYA to disappear other than ammonia but what would create that? And how can I test for it?

FYI I know how to fix it with stabilizer and SLAM just interested in how to prevent it and what on earth would create it.

 

[PAGirl]

What was your starting CYA level? Do you have an auto fill or have you gotten a lot of rain recently?

 

[Dkoucky]

It was 45. But like I said I was cheating on my tests so that was prob 4 weeks ago. It held fairly steady all summer since the last bout of this...

I have definitely gotten rain but not record amounts or anything just a couple of inches. Some leaves have started to fall and a few were stuck under the cover. Not many but prob not good for my water quality.

 

[pooldv]

CYA can be consumed by bacteria when FC is low and the circumstances are right. It is fairly rare but it sounds like the conditions are ripe for it in your pool this year. Maintaining FC above minimum will keep the algae at bay and the bacteria eating your CYA away also.

Ammonia is created by the bacteria consuming the CYA. Ammonia doesn't consume the CYA.

 

[Dkoucky]

Thanks! Looks like I just need to be more vigilant, it get hard to be motivated when the whole family is tired of swimming for the season.

Although the price of stabilizer is a pretty good prod.

 

[pooldv]

Nothing motivates occasional FC testing like some algae! :-D Don't ask me how I know.