New SWG, trouble keeping chlorine in pool.

[jmag999]

At the beginning of the season, we installed a new SWG in our Plaster pool. Previously we used tablets in a CL220, which always worked fine.

I am now struggling to keep Chlorine in the pool. We have a solar system along with a VSP, so depending on how much sun we get, the flow is either very high or very low.
When it was sunny, the levels kept up fine, however, last week was very rainy and when the sun came back out several days later, I found that the pool had no chlorine. I shocked the pool and got the level back up, all was fine for a few days.

2 Days ago, Chlorine was 3ppm. We did not use the pool yesterday. This morning the pool looked like it was starting to get cloudy, so I tested the chlorine and got 0 again!

Here are the results of my testing:
FC: 0
pH: 7.6
TA: 100
CH: 310
CYA: 70 (must be from previous tablet use?)

Am I just not running the SWG long enough? I was thinking of switching the pump schedule to run for X hours per day at high speed with the SWG set to 100%. It seems strange to lose that much chlorine in 1-2 days.

 

[Mr Bruce]

Are you saying you run your pool equipment off solar?

Can you fill out your signature with your pool and equipment details please?

Do you have a salt test (preferably the K-1766)?

Thanks!

 

[jmag999]

Sorry, we have solar heat. The pool is not powered by solar.

I updated my signature with pool details.

 

[Mr Bruce]

Awesome, thanks.

You will need to run your SWCG at 50% 24/7 or 100% for 12 hours per day to keep up.

 

[jmag999]

Is the runtime due to my CYA level? Should I get that lowered? It looks like 70 is recommended.

Is it normal to have to run the system for so long with a SWG?

Does the speed of the pump (flow through salt generator) matter in terms of chlorine production? Or can I run it at 1200rpm for 12 hours per day?

 

[Mr Bruce]

The rating for the SWCG (in your case 60,000 gallons, that's what the 60 in RJ-60 means) is for 24/7 x 100%. So for your pool, it only needs half of that. This is why we recommend SWCG way oversized for the pool. Your CYA is perfect.

As long as the flow switch is activated it is producing chlorine. Slow (or fast) enough to trip that is plenty. There is no gain in running at a higher speed.

We have similar setups/sizes. I run my SWCG 24/7 on low at 50% fwiw.

 

[jmag999]

Thanks so much for the help. I will give it a try.

 

[the_sphynx]

FYI, my SWG is a IC-40 so different but my SWG kicks on about 1500RPM. I have it set to 1700 just for skimmer purposes and to account for various fluctuations that just happen. For you sending those through your solar system on a roof then your pump may need to run higher to account for the vertical lift up to your solar setup...

 

[jmag999]

Yep, I just did some experiments to see what the minimum speed would be. 1500 RPM was what I came up with also. When the solar is off, there is an automated bypass so that I am not pumping the water to the roof when it's not needed.