SWG making too much Chlorine

[JohnAJohnson]

My SWG is set at the lowest level (20%) and my chlorine level stays at 5-6 ppm. I'd like to keep it no higher than 3. I am running the pump for 5.5 hours per day; any less and the pool isn't filtered adequately. I turned the SWG off to let the level drop down to 1 and it took almost two weeks, but when I turned it back on to 20%, it brought the Chlorine level back up to 5 within a few days. Is there something else I can change in my chemistry that will help the chlorine dissipate faster? I really don't want to buy a smaller SWG. Here's my setup and numbers, and thanks in advance!

- Wife and I swim for 2-3 hours a day. We are the only bathers.
- Sun hits the pool for 8 hours a day. The pool cage (screen) filters some of the sunshine, but not much.
- Ambient temperatures have been mid 90's in the day dropping to mid 70's at night.
- We keep the pool at 88 degrees and by late afternoon, it's up to 92 or so.
- Test equipment: K-1766 Taylor Kit for Salt, LaMotte Instat-Test Strips for Borate, TF-100 Test Kit for all other tests

Salt: 4200
Total Chlorine: 5 (using K-1000 Test Cell)
pH: 7.5 (using K-1000 Test Cell)
Chlorine Drop Test: 5 free, 0 combined
Total Alkalinity: 80
Calcium Hardness: 160
CYA: 80
Borate: 50

 

[anonapersona]

You might check the owners manual on the SWG, that salt level seems high. If that is in range, then check about the recommended level of stabilizer/conditioner/CYA. If both are high, a partial water change would be needed. This would change the levels of calcium, borates, and total alkalinity which affects pH. Those levels are perfect now so you would need to get them tested and adjusted.
Please do wait for someone here that knows more, I just wanted to get you looking for the instructions.
I will offer a suggestion that with the screen enclosure, the CYA level may need to be lower. By how much, I don't know. If the salt is too high, you would drain enough to fix that, then do not add any CYA until you see how it is doing. It may be that the borates are also helping to keep chlorine up. Yours is a case of too much of a good thing it seems

 

[duraleigh]

You can lower your CYA to around 20-30 ppm but it will involve draining and refilling more than half of your pool.

Can you put the swg on it's own timer? I agree that your pump run time is pretty low but if you could run pump 8-10 hours and swg 4 hours that would do it.....it'll cost some money but perhaps cheaper than draining and refilling about 60-70% of your pool water.

PS - The cage blocks much more sun than you think.

 

[anonapersona]

Timer-- what an elegant solution!

 

[JohnAJohnson]

You might check the owners manual on the SWG, that salt level seems high.

Pentair calls it in tolerance, but it is on the high side. I usually run it at 3500 but after 10" of rain in two days, I drained a lot of water out of the pool and guessed wrong when I added salt. :?

I will offer a suggestion that with the screen enclosure, the CYA level may need to be lower. By how much, I don't know. If the salt is too high, you would drain enough to fix that, then do not add any CYA until you see how it is doing. It may be that the borates are also helping to keep chlorine up. Yours is a case of too much of a good thing it seems

Good suggestion, thanks.

 

[JohnAJohnson]

Can you put the swg on it's own timer?

Yes, but I've been avoiding that if there is a better way. Right now, the pump and SWG are using common wiring from the CB Box and while I could run a separate line, and I do have an extra relay on the PE153 Timer, it would add complexity to something I'd like to keep simple. But good suggestion, and I may end up there eventually.

PS - The cage blocks much more sun than you think.

I think you might be right. I'm out there every day in the hottest part of the afternoon and haven't burnt yet :-D

 

[sd72667]

Just leave the SWG off. When my FC was high, I turned off the SWG, added water, drained to waste several times until the FC was normal. I usually keep my salt level around 2900-3100 ppm, which for me keeps everything balanced. I am always testing and cleaning my pool. I am obsessed. It is therapeutic for me when I am cleaning my pool. Good luck.