SWG, FC levels, and pool cover

[akropp]

I am having a tough time maintaining a consistent FC level with my SWG. At issue is that I have an autocover that may remain closed for days at a time (I have little kids, so don’t want to leave it open when not in use), but then some times it will be open all day for a couple of days. Every time I leave it open, I end up having to turn my SWG up to keep the FC levels above 2, but then if I don’t turn it way down, after a couple of days with the cover closed my FCs climb up to 10+, so that I have to leave it open just to let the sun burn off some of it.

Is this normal to have to be constantly tweaking the SWG level? It wouldn’t be such an issue if I were home, but my wife doesn’t want to be messing with this while I am at work, depending on whether the kids are going to use the pool or not, so I am always guessing (often wrong) whether to run it high or low for the day.

Is this the reason the recommended CYA level is so high? My pool installer told me not to bother with stabilizer at all, and I asked on here and someone said I would be fine at 50, but I’m wondering if that’s my problem.

My tests this morning:
FC: 10
CC: 0
CYA: 45
TA: 70
PH: 7.4
Salt: 3200
CH: 400

 

[DorsalSpine]

This is my first year with an auto cover and I'm having similar problems. I have tracked FC for years so I know what to expect from the pool. It's different this year. What seems to help is to open the cover for a couple of hours every day or every other day. The pool is fenced and we don't have kids at home so I don't worry about it. Usually, I check the pool after dinner, adjust the chemicals as needed, wait until bedtime to go close the cover.

 

[akropp]

Yeh, I’ve had to have my wife leave the cover open sometimes during the day. She really doesn’t like to though, with two very active kids in the house. Our yard is fenced, but there’s no fence between the house and the pool (the main point of the autocover!).

 

[Kjp300]

Same problem here. I do exactly what you do. Raise the SWG when the pool is being used, then lower it when not in use. And many times shut it down completely. I run my pump 24/7 so it is just a matter of testing and adjusting the SWG. With pool math I have a pretty good idea about how much chlorine my SWG generates at certain percentages, so I am getting a pretty good feel for it. I also keep my CYA at 50. I do try to keep the cover open a couple hours a day. My pool area is fenced in though and is separate from the main yard, so the pool area is off limits even when the cover is open.

A word about pool builders. They may know how to build a pool, but they may not know anything about water chemistry, especially if they have been in the business for a while and are using outdated information. My pool builder has been building pools for 30 years and was great and I would recommend him to anyone to build a pool. But he said the same thing about CYA with an auto cover, don't worry about it. After finding this site, I quickly learned that I understand the FC/CYA relationship, and he does not.

I have a large yard, and the PB is the one that suggested even with the auto cover that if I can fence in just the pool area it is much safer than fencing in the whole yard, for the reasons you pointed out. I would never have thought about that but he is correct. No little ones in the pool area ever and they can still enjoy the yard.

 

[DorsalSpine]

Just to be clear unless my wife swims I open the cover when I get home from work and close it sometime that night. I wouldn't want it open during the day if I had kids at home. In the evening I'd have much better control of who was where. On occasion I do have grandchildren to keep an eye on.

 

[Msch99]

When cover is open for extended periods, UV Ray's burn off your FC. Probably just need to learn 2 settings on swg, one for cover closed and one for open. Or set swg for when closed, then add liquid CL when you open it up, amount would depend on swimmer load, direct sun, time open to sun etc.

 

[mknauss]

I believe that some automation systems will adjust the SWCG out put when the autocover is on the pool. You might research that and consider investing in an automation system.

 

[mguzzy]

...
Is this the reason the recommended CYA level is so high? My pool installer told me not to bother with stabilizer at all, and I asked on here and someone said I would be fine at 50, but I’m wondering if that’s my problem.
...

What @Msch99 said... I've learned to adjust my SWG when the cover goes on and off. Sometimes I'll leave the SWG a little high and put the cover on specifically to get my CL up. its just the way it works.

And no that is not the reason they recommend higher CYA levels for SWG pools. That recommendation is for pools with or with covers.

 

[akropp]

I believe that some automation systems will adjust the SWCG out put when the autocover is on the pool. You might research that and consider investing in an automation system.

Sadly I have an automation system already (AquaLink), but the builder used a Hayward SWGC, and it is my understanding (from another post here) that AquaLink won’t talk to the Hayward. Not sure why they didn’t put in something compatible in the first place, since it was all installed together.