Need help adjusting my SWCG

[JB007]

HI. so i started my Circupool SWCG yesterday morning and had it set to run for 11h yesterday (my pump runs 12h). Before starting, i tested chlorine at 3.2ppm (Yesterday morning). I put the setting to 75%.
This morning, my chlorine level was at 5.2. Circupool instructions says to wait a couple of days before testing, but with such an increase in 24h, i may be at 10ppm in 2 days.

i dropped my out put to 35% this morning as I wanted to reduce the level to get closer to 3.
But was wondering if it is better to leave it at 75% for only 4h instead of doing 35% for 11h ? what is better for the longevity of the cell and the control of output ?
any input on how to start this up would be great.
Thanks.

 

[Texas Splash]

is better to leave it at 75% for only 4h instead of doing 35% for 11h ?

It doesn't matter. Whether you run a cell at 100% for 12 hrs or 50% for 24 hrs, it's using the same amount of cell plate life. Just be sure to keep the FC at a good strong level as noted on the FC/CYA Levels. Best to never let the FC fall to the minimum if you can help it, especially in the summer (algae). If you have more questions let us know.

 

[dfwnoob]

Additionally, save on reagents. Use 10mL of water for your chlorine test and 1 heaping spoon of powder. 1 drop will then equal .5 FC. So 10 drops = 5 FC.

 

[BDY]

I recommend the PoolMath app effectof adding function - if you pick SWG and put in your size of SWG (daily output in pounds per day) then enter pool size, SWG % and pump time it calculates FC generation fairly accurately

 

[Jimrahbe]

JB,

Why do you want your FC to be 3 ppm? What is your current CYA?

The basic idea is to keep your FC at your Target FC or higher. It is not to try to stay between the minimum and your target.

If your CYA is at 70, your Target FC is 5 to 10 ppm.

Thanks,

Jim R.

 

[JB007]

Thanks for the replies!

ok on the cell life and testing (good idea, so used to do the 25ml)

i get it, to have a strong FC, but the fact that it went from 3.2 to 5.2 in 1 day, doesn't that tell me that i need to drop the output a little ? in my mind if I leave it at 100% again for 11h, it may take another 2-3ppm
I will test it tonight again to see where it stands, knowing that i dropped the output to 35% for today.
will use the PM app too to see adjust.
was so used to my LC, had it down to a science...hope i wont regret it

 

[Texas Splash]

but the fact that it went from 3.2 to 5.2 in 1 day, doesn't that tell me that i need to drop the output a little ?

Eventually, yes. If it keeps growing. Our concern right now is that you are on the low end and could leave yourself open to algae.

Me personally, I almost never use my super chlorinate or boost function. It's not very predictable and takes too long. If my FC is low, I add a little liquid chlorine to ensure I get a rapid, accurate FC gain, then adjust my cell as needed.

 

[markayash]

If you leave it on the low end you will get algae and have to spend a ton on liquid chlorine to fix it. Lot of us know from experience, I had mine at 5 in spring because the water was still cool and due to a lot of rain and pollen algae took over

 

[Jimrahbe]

JB,

It is like anything new, it takes a few tries to get it right.

You will not regret getting a SWCG.

The key in my mind is to not try and micromanage the cell. If you try to keep an exact FC number, it will drive you crazy. Your pool will use more or less chlorine as the weather changes, sunny days vs. cloudy days, more swimmers vs. no swimmers, etc.. I only worry about one thing. I just want to make sure my FC stays at or above my Target FC.. Running a little hot is not a problem. Letting it get too low is.

You'll get the hang of it soon..

Thanks,

Jim R.

 

[BDY]

I think it was either Jim or Newdude who wrote once that they only adjust if it starts getting into the teens and I took that to heart for my SWG. I had to slam at a high CYA and I don’t ever want to do that again. I’d rather run a higher FC esp as it’s safe up to slam

 

[Newdude]

I have said that and I'm not alone.

+1 to not micromanage. Make sure you are covered for the high UV / batherload days. Accept that you'll overproduce on the other days. Otherwise you turn it down today 10% (?) and will need to turn it back up in 2 or 3 days.

At some point, enough is way enough, so I step in at 13, let it drift back into target range (5 to 10) and turn it back on. However, by being absolutely sure I produce enough FC, my testing is not always all that frequent. I've lost count how many times I 'caught' it as a 17 or an 18.

 

[dfwnoob]

What he said.

Been letting my SWCG just do it's thing for the last couple of weeks since it's actually been getting hot. Last few days have included a lot of overcast and rain, though. Finally tested it this morning and I was at 15. Oops. Turned it down for the day and set a reminder in my phone to turn it back on tomorrow.

 

[Newdude]

set a reminder in my phone to turn it back on tomorrow.

None of us are 'membering like we used to.

 

[JB007]

OH Gosh. I guess I just need to get used to it.
I think I micromanaged it too much when I used LC and have that same drive to do it with the SWCG, LOL.

In all what I read above, I see the big point : better shoot on the high side to prevent the algea issue and prevent the slamming (with a higher CYA than under LC). It all makes sense.
Thanks!!

 

[wireform]

I always recommend to run the FC on the hot side so when the FC slipps up your still well above anything to worry about. FC within the cya ratio is completely safe and nobody will ever know the difference except the water.

 

[generessler]

I guess this has become my mantra. Numbers can help see what's happening.

Looking at the spec on Amazon, your cell produces max 3.1 pounds of chlorine per day. That's at 100%.

The 17K gallons in your pool weigh 8.34 pounds/gallon * 17,000 gallons = 141780 pounds.

So the SWG is putting 3.1 parts chlorine in 141780 parts of water. 3.1 / 141780 is a tiny number. So we use ppm instead. That's just

3.1 / 141780 * 1,000,000 = ~22 ppm every day at 100%. That's a good number to keep in your head.

So you can see why just one night increases FC quite a bit. It's a big cell for a mid-size pool.

But that's a good thing. All you need to do is set it to the fraction of 22 ppm that offsets daily loss. Say you'd normally lose 3 ppm per day at this time of year. That's 3/22 or about 14% of the cell capacity.

You can set the cell to 14% and run it 24 hours a day. Or you can set it to 28% and run it 12 hours. Or 56% and run 6 hours. You get the idea.

This is just to give you a starting point and show it's not magical. Unless you're lucky, it always takes a bit of tweaking like you're doing now to find a good setting. There have also been some reports here that Circupool exaggerates their production rates. Ymmv.

You can duplicate this calculation with the "effects of adding" part of the Poolmath app. I just find it's not worth the trouble.