Dialing in a SWG

[Wild Duk]

when trying to determine where to set the output on my SWG, what part of the day shouldI test the chlorine to determine if I turn the SWG up or down?

[teppy]

i'm certainly new to this myself, but i am doing my testing in the late afternoon. i feel like since the sun has been out all day, my chlorine usage should be greatest then.

i have been slowly cutting back on percentage and still making lots of chlorine. i have it down to 40 percent now. my chlorine level was still at 7.5 yesterday afternoon. so, i cut back my pump run time to exactly 8 hours. i don't want to go lower than that since that it the 'magic' number recommended. if i still have too much chlorine, i will cut my percentage down on the SWG again.

[New2Me]

I test after the sun is off of the pool. That should be my lowest CL reading, and I want to maintain that ABOVE the lowest recommended level. SWG runs after taking reading, building CL level until next period of sun-loss.

[JasonLion]

Wild Duk, as the others already said, late afternoon or early evening, which is when the FC level is normally lowest.

teppy, There is nothing special about 40%, you can simply reduce the percentage.

[teppy]

i was referring to the 8 hour run time.

teppy, There is nothing special about 40%, you can simply reduce the percentage.

[PVille]

I will typically test late afternoon also. The important thing is to test at the same time each day and in similar weather conditions when you are trying to dial it it". I also keep a small notebook and a pen in a baggie on top of my test kit. I take notes during each test of the test values, weather, water temp and any issues I might be having. Really comes in handy down the road if you see a problem you know you solved before.

Once I get my chlorine to hold at around 3. I know I just have to run a super-chlorinate cycle if it rains or we have a big crowd to get things back in shape.

[Wild Duk]

Thanks, I started testing at the same time each evening......If free chlorine is the lowest at that time, and you get a drop overnight, at what time would free chlorine be at its highest level.......I normally run the pump from 9 to 9 in the summer....Would it be toward the middle of the pump cycle???

[New2Me]

you get a drop overnight

It shouldn't drop at night, unless you have algae or something using it up. Normal daytime loss is due to sunlight.

at what time would free chlorine be at its highest level

As soon as your SWG shuts off. If you have one that runs a percentage of pump run time, then you'll have to figure out when that is.