Getting percentage generation right

[pollyAnna]

Hi
This is our second season with a SWG. We're 4 weeks into this season I use the pool math app to set & adjust my SWG. Does the run time & percentage numbers take into account natural daily loss? What is typical daily loss? Per the app to replace 4ppm i need to run my generator for 20hrs at 50% this seems a lot. What am i missing? My CYA is at 65-70

 

[mknauss]

Which Pureline SWCG do you have? Please add that to your signature.

You set your SWCG to generate your average daily loss of FC. So if that is 4ppm, that is what you want the SWCG to generate.

 

[Jimrahbe]

Ann,

You will just drive yourself crazy trying to get your % exactly right... Look at the bigger picture and try to adjust your SWCG so that your FC stays at your Target.. If it goes higher on the days where the sun does not sun, just don't worry about it, a little high won't hurt a thing.. The only important part is to make sure it never goes too low..

Most pool use between 2 and 4 ppm of FC per day.. Obviously, pools in Arizona use more FC than pools in the North East. Each pool is different, so you will just have to determine how much your pool uses.

If you don't want to run your pump for 20 hours with your cell at 50%, then reduce your run time and increase your percent of output.. The Cell does not care.

Thanks,

Jim R.

 

[laprjns]

Hey Polly, I don't think you are missing anything. We got essentially the same setup, about the same pool size, same pump, same SWG, even the CYA level. I'm also on my second year with my SWG and pump. I'm running my 60K Pureline SWG at 35% for 18 hours, which according to PoolMath generates 3.3 ppm per day. It's keeping up with the demand. The last time I changed my percentage was 15 days ago.
Based on your numbers, I'm assuming that you have a 40K SWG which should be producing around 3.6 ppm per day. Sound right to me.

 

[pollyAnna]

Which Pureline SWCG do you have? Please add that to your signature.

You set your SWCG to generate your average daily loss of FC. So if that is 4ppm, that is what you want the SWCG to generate.

HI We have Crystal Pure 3.0, 40K gallon.

My filter is set for 8hrs on 4hrs off, 8 on 4 off is this is good cycle? Is a dual cycle of longer on during daylight and off at night a better set up?
We are currently set ~50% thinking this should replenish my ~4ppm daily loss over the 16hrs.
Thank you

 

[mknauss]

You are generating 2.9 ppm FC at a 50% generating level running for 16 hours each day.

Why stop and start the pump? Change it to 24 hours per day and you will generate the 4 ppm FC per day.

 

[pollyAnna]

You are generating 2.9 ppm FC at a 50% generating level running for 16 hours each day.

Why stop and start the pump? Change it to 24 hours per day and you will generate the 4 ppm FC per day.

Interesting suggestion. I have it on full power for 8hrs then off. I guess i could try full power for say 4hrs to get a good turn over then have it tick away at a lower rpm (right units?) for another 20hrs. There by maintaining steady generation.
Is 50% a "reasonable" level? For some reason I had the idea it should be lower to prolong cell life, so have been trying to run at 30-40%.
The goal is no algae so i guess, answering my own question, run the swg at the needed level - the cell might not last as long but we can use the pool the whole season (no more slam every 3rd week).

 

[mknauss]

I cannot imagine there is any reason to run the pump 'at full power' ever. Turnover is meaningless. Run the pump at sufficient RPM to provide skimming and close the flow switch on the SWCG. Beyond that, if you use a manual vacuum or similar, you might have to run the pump at a higher rpm to make that work.

The SWCG has a finite number of generating hours. It does not care if it is on at 50% for 24 hours or 100% for 12 hours.

 

[Jimrahbe]

Ann,

"Full Power"????? Kind of does away with the whole purpose of owning a VS pump... I run mine at about 1200 RPM... Cost me less than $20 bucks a month.

If you have a heater you might have to run about 1600 to 1800 RPM.

I agree with Marty... no reason to ever run at full power..

Thanks,

Jim R.

 

[pollyAnna]

Thank you all for your advice
I've set my filter to 24 hours at a 2100 rpm - a significant reduction from 3200! I'll monitor and see about reducing further once I'm comfortable.....