Chlorine too high

[qwert189]

I have a pentair IC40 on an indoor 12000 gal pool/ 1300 gal spa combo. I run my Intelliflow VSP ~1300 RPM for 6 hr/day on the pool and 4hr/day, with the IC40 set at 11% via the intellicenter app. 11% is the lowest it goes before it starts doing a green blinking light on the output indicator light on the IC40.

Running it at that speed/length still keeps my free chlorine at 5-6% (I have 0 CYA as an FYI, indoor pool) all the time, which feels a little harsh on the skin. I have been able to keep it at ~2% FC if I push my pump down to 900RPM and drop the circulation time to 4hr for the pool and 3hr for the spa, but the IC40 starts blinking red indicating it's not getting enough flow when I do that, and I'm concerned I'm not doing enough turn-overs on my pool

My question for the group, should I run the IC40 at <10% and just let the IC40 blink green (low output) at me all the time? Should I run at low RPM and let it blink red (low flow) at me? Should I keep settings as is, but reduce my pump run time by half (3hr for pool, 2 hr for spa)? It's about ~20gal/min at 1300 RPM, so @6 hr it will do 1/2 a water change a day, and @3hr it would do 1/4 a day.

How do others deal with an SWG that is overproducing?

Thanks!

 

[PoolStored]

HEY! We got you.

(I have 0 CYA as an FYI, indoor pool) all the time, which feels a little harsh on the skin.

For indoor pools, we recommend having ~20ppm CYA. Having 2 ppm FC with no CYA will have an active chlorine level that is about 20 times higher than the typical outdoor residential pool with an FC that is around 10% of the CYA level. CYA doesn't just protect chlorine from sunlight, but hugely reduces the active chlorine (hypochlorous acid) concentration. If you do decide to use some CYA in the indoor pool, don't overdo it. Use a small amount, say no more than 20 ppm, and then have your FC in the 2-4 ppm range and see how that works for you. If you find a buildup of Combined Chlorine (CC) over time, then you can use non-chlorine shock (MPS) every once in a while to get rid of organics (mostly urea) that aren't dealt with as quickly without exposure to sunlight. Doing this will be less harsh on the skin and bathing suits.

I'm concerned I'm not doing enough turn-overs on my pool

Turn-over in a pool is a myth. We run the pump to skim, filter, chlorinate (SWCG or tablet feeder), circulate (mix chemicals) or heat. Run your pump for one of these purposes. So for you, with the SWCG, run your pump long enough to add enough chlorine for your CYA level to keep the pool chlorinated. Run the pump with enough speed to engage the flow switch +100 RPM...this will give some buffer on the pump speed.

Hope this helps!

 

[Jimrahbe]

Q,

The flashing lights just mean you have the output set to less than 10%. It is not a problem, the IC40 just wants you to be able to tell the difference between say 5% and 50%. This really only makes a difference when you are using the IC40 to do the adjustment. If you have an automation system, you get an actual number that you can adjust.

Thanks,

Jim R.

 

[qwert189]

Thanks PoolStored and Jimrahbe! I think that answers everything for me, it's good to know I have more freedom than I thought to play w/ my schedule and chlorination rate.

I'll crank down the pump frequency a bit (will save me a bit money on my bill as well), add a bit of CYA, and drop it to ~5-6% on the intellicenter (letting the IC40 do its green blinking to indicate it's below 10%). I bet w/ those I'll be able to get FC perfect.

 

[DavidArmenB]

To reduce FC levels, you can not only reduce pump run time, but you can reduce the time that the SWG is on. Chlorine concentration is based on two things. The percentage on the SWG and the length of time that SWG is powered. You can run your pump however long you want and only run the SWG for two hours a day for example. You can also play with the percentage: 4 hours on 10% is the same thing as 8 hours on 5% and 2 hours on 20% etc.