FC/CYA as a Function of Season & Covers

[CaptainUnderpants]

In my 18 months of pool ownership I have learned a lot from this forum. One is that guidelines are just that guidelines. The CYA recommendation for an outdoor SWG pool is 60-80. But what about winter when the sun is about 1/2 as strong, or even during the summer when a cover is on the pool for a good portion of the day?

Many here have put their pools away for the winter, or if you are in Florida, you still get strong winter sun. I am in SoCal, which is only on the latitude of Virginia. SoCal winters by the beach are very mild to non existent yet the sun is not nearly as strong. As of today my CYA reading is now down to 60, as I haven't put any in within the last 2 or 3 months. At this point the recommended FC/CYA says to get ready to raise my CYA, but should I wait until March of next year? It's winter here and my pool stays covered all day.

Would not another CYA range apply, something more like 40-60 for my scenario?

 

[mknauss]

Re: FC/CYA Relationship as a Function of Season and Pool Covers

CYA is used to protect the FC from the UV of the sun. So, in the winter, with much less UV, you can have lower CYA. I let mine drift down over winter as it normally oxidizes over time. In March I will check it and bump it to 80.

If your FC is holding then CYA does not need to be added. The issue in the summer is the sun can consume the FC faster than the SWCG can create it. Thus the CYA protects the FC and does not allow that to happen.

As you stated, the ranges are that, ranges for consideration. Understanding your pool and how it reacts to chemical levels or additions is very useful for a TFPC way.

Take care.