How to Measure SWG Performance & FC Production

[Toxophilite]

Moved from HERE

I live in Ohio. Sunny 80 degree day with swimmers, I lose 5.5-6.5 per day.

I don't have my SWG, YET!!!! But, with constant run of SWG, how would I measure loss? I assume the SWG settings can be a close fit, but with notional number dials anything else can be actually generated I would assume. Maybe, turn the SWG off a day and measure loss?

 

[PoolStored]

Start FC - End FC = net loss

FC Added + net loss = total loss.


Example
7 - 7.5 = -.5
-.5 + 3.8 (40% SWCG at 24 hours (MINE!)) = 3.3 total loss.

Just substitute how much your SWCG added in FC. The 3.8 is just an example using my SWCG.

 

[Homebrewale]

You can run a test like the OCLT except from sunrise to sunset. I would run the OCLT first to confirm there isn't any algae. If you are sure there isn't any algae, the daytime loss of FC should be all due to UV.

 

[Toxophilite]

Start FC - End FC = net loss

FC Added + net loss = total loss.


Example
7 - 7.5 = -.5
-.5 + 3.8 (40% SWCG at 24 hours (MINE!)) = 3.3 total loss.

Just substitute how much your SWCG added in FC. The 3.8 is just an example using my SWCG.

Thanks! That would be my question, basically, is how does one get the value for the amount the SWG is putting out, which I guess is a total increase for 24 hour measurement, less the loss, but loss is determined from daily increases. When I add chlorine now, I know the start and how much chlorine added. When I go SWG, and it's adding constantly, other than what a setting says, there's no measure of actually how much was added for the day.

 

[Texas Splash]

Another way could be:
1 - Do an Overnight Chlorine Loss Test to rule-out excessive loss to organics.
2 - Go to the PoolMath APP and determine how much FC is expected to be produced in a specific time frame; I'll use 6 (nighttime) hours for example.
3 - Turn the SWG at 100% for those 6 hours of darkness (no loss to UV).

If you started the nighttime test at 4 ppm, and the Poolmath predicted you should generate 3 ppm in 6 hrs, then theoretically you should have increased to 7 ppm. Or at least 6 ppm if you lost 1 ppm to normal organic loss.

 

[Toxophilite]

Another way could be:
1 - Do an Overnight Chlorine Loss Test to rule-out excessive loss to organics.
2 - Go to the PoolMath APP and determine how much FC is expected to be produced in a specific time frame; I'll use 6 (nighttime) hours for example.
3 - Turn the SWG at 100% for those 6 hours of darkness (no loss to UV).

If you started the nighttime test at 4 ppm, and the Poolmath predicted you should generate 3 ppm in 6 hrs, then theoretically you should have increased to 7 ppm. Or at least 6 ppm if you lost 1 ppm to normal organic loss.

Thanks! I did see some complicated method here of measuring water before and water from return over a time frame, but seemed hard. But, I guess the idea is "know" the actual output and/or output condition of your SWG, since the number will be used to accurately predict more important things down the road. That original thread got me to thinking, but now, the whole mind-bend over that blind measure of FC seems a little easier.