CYA Loss

[simonoaks]

Hi,

I have posted a couple of time about this over the last few years, and still do not really have a good understanding of what is causing it.

I noticed a gradual loss of FC , even though we are away from mid summer so technically I should be lowering my % on SWG as less sun on my North facing pool. However there is a gradual loss.

I tested CYA yesterday and it was way less than 30.

So I have gone from over 90 to less than 30 in 4 months. This is a common trend year round, every year. Any idea what is causing my CYA loss?

thx

 

[ping]

Do you have an autofill for your fill water and/or an overflow for the pool if it gets too much rain?

Are the salt levels stable in the pool or do you have to add salt every now and then?

 

[simonoaks]

Do you have an autofill for your fill water and/or an overflow for the pool if it gets too much rain?

Are the salt levels stable in the pool or do you have to add salt every now and then?

I manually fill pool, usually every 10 days , sometimes 7 days (it has been a very dry summer this year), maybe 2-3 inches fill per week.

We have not had enough rain to over fill pool this year.

I add a bag of salt about every 2 months.

Do you think I have a leak? I can imagine that is almost impossible to trace and fix. There is certainly no leakage around any of the main above ground equipment / pipes.

thx

 

[ping]

Since you are adding salt every 2 months I would highly suspect a small leak. In 7 years I have only added 2 bags of salt to make up for lost salt due to backwashing.

 

[manfacro]

I read on here someplace that Sun & heat can kill CYA. I’m also in Florida and this last month and a half I lost 30ppm of CYA, to the point where I went back to using the chlorine tablets I had in storage (using poolmath to help calculate CYA) to start building it back up.

 

[mknauss]

High water temperature (90+F) can accelerate the degradation of CYA. I see up to 15 ppm per month during the summer.

 

[BasicTek]

I also see about 10 - 15 loss per month over the summer and still 10 loss per month in winter. I maintain a very hot pool around 90 from April to October and probably averaging around 80 from November to March. I have used only 1 bag of salt this summer and 1 last winter (3 last summer mostly due to irma) so I don't seem to be loosing as much salt. My pool does overflow a bit during the FL rainy season but I lose almost as much CYA in winter also with almost no rain and the pool covered. It's done this for 2 years so I've come to accept it's just what my pool does.

To note CYA can be bought extremely cheap in bulk on ebay, even cheaper when they have coupons. I actually bought a 4 gallon pack the liquid since I have to add it so often it was about $60 on ebay coupon deal (not available now). I'm on gallon #2 since June so it will probably last me a year and a half or so. I also float some leftover pucks I have on occasion...

 

[duraleigh]

I manually fill pool, usually every 10 days , sometimes 7 days (it has been a very dry summer this year), maybe 2-3 inches fill per week.

We have not had enough rain to over fill pool this year.

I add a bag of salt about every 2 months.

Do you think I have a leak? I can imagine that is almost impossible to trace and fix. There is certainly no leakage around any of the main above ground equipment / pipes.

thx

Almost for sure, You have a leak. Florida climate should result in a 1/4 or LESS daily loss. That would explain your salt and CYA loss, too.

Perform the bucket test to confirm but plan on the result being a leak.

Pool School - Leak Detection