Help! SW Chlorinator, High Chlorine + something growing, but clear!

[Bird Dog]

Hi,

It's Woody in CT. 35K gal, SW chlorinator, chlorine is reading 11.5 ~12! Consumed chloramines 0.5! Pool looks clear but the chlorine level should not be anywhere near that high. I usually run her ~ 4 to 4.5. Nutz. Salt level is 4K. Why is the chlorine so high? How do I fix it? Should I SLAM? Where should I take the chlorine level on the SLAM if I do ~ 20?

Here's some pics.

Wierd.

 

[Texas Splash]

Your description is confusing me, so I want to make sure I understand. You mention the water is clear and the FC is riding higher than normal, but then ask if you should SLAM? If you see no algae, and the FC is holding well, there is no need to do a SLAM Process. To reduce the FC level, just lower the SWG output and/or reduce pump run time to reduce FC production.

If you had algae, that would normally result in cloudy water and trouble keeping the FC where it needs to be. But if you think you have algae, you can always run an Overnight Chlorine Loss Test as a test.

 

[jmastron]

Has the cover been on during the day more than before? That will reduce the FC (Free Chlorine, the "good chlorine") burnoff from the sun during the day, and if the SWCG is set at the same production the FC level will indeed climb. When my solar cover is on all day, I cut the SWCG time in half (if not more) to keep FC from climbing more than I want it.

The SWCG doesn't have a feedback loop and doesn't know the FC level -- it just generates based on the time/percentage. You dial that in to match your pool's usage, which can be very different cover on/off as well as in different seasons.

As Texax Splash stated, if CC (Combine Chlorine) is only 0.5 and the water is clear, and FC is holding (which it seems like it is!), you probably don't have anything growing. Posting a full set of results (FC, CC, TA, CH, CYA) would help us diagnose further.

 

[Jimrahbe]

BD,

Your salt cell has no brain. It will just make the amount of chlorine that YOU tell it to make.

It is up to you to adjust the cell's output to keep the FC in the range you want it.

Also.. Without knowing your CYA level, it is impossible for us to know if your FC is too high or too low.

You need to keep your FC and CYA in the proper relationship per the saltwater section of this chart. FC/CYA Levels

I recommend that you maintain your "Target" FC or a little higher and never, ever, let it get close to your minimum.

Thanks,

Jim R.

 

[Rancho Cost-a-Lotta]

Here's some pics.

Pic assist:

 

[Bird Dog]

Thank you all. CYA is 50. SW Chlorinator is set at 4. I guess I can try throttling it back, or, as suggested, turn off the pump entirely. I agree TS that it is WEIRD. Never happened previously. How does a SW chlorinator keep the FC at ~ 11+? It's been a couple of days. Also, why/how am I getting a consistent CC of 0.5 - 1? That says something funky is living in the water to me, but what do I know?

 

[mknauss]

auto Pool Cover

Do you keep that closed much of the time? @jmastron asked the same above ---

 

[Bird Dog]

Yes, I typically keep the pool covered when not in use. It was open all day yesterday and again from this am until now.

 

[mknauss]

The cover will trap CC. Only test CC after the cover has been open with sun shining on the pool surface for several hours.
It will also dramatically reduce FC loss due to UV. So the SWCG generation needs to be adjusted to match the time the cover is closed during daylight hours.

 

[Rancho Cost-a-Lotta]

What are your photos showing? Water appears a bit cloudy maybe?

 

[Bird Dog]

What are your photos showing? Water appears a bit cloudy maybe?

The pics were from this am, and there was a bit of cloud cover, but I would largely characterize the water as clear. I had plenty of green water in the past when algae was growing and SLAM'd successfully. But I am seeing CCs in the tests which is WIERD, which also gets my mind to read the water as having a touch of green. I am a bit crazy. Robot is in 9' in the pics for reference purposes.

 

[Jimrahbe]

BD,

Your "problem" is the auto-cover, which is not really a problem at all. It just means you will have to adjust the way you run your cell based on the cover being open or closed for long periods of time.

Thanks,

Jim R.

 

[Bird Dog]

Cool, thank you all. I'm going to leave the auto cover open and shut the pumps down for the day and retest. I'll keep you posted.

 

[Rancho Cost-a-Lotta]

But I am seeing CCs in the tests which is WIERD, which also gets my mind to read the water as having a touch of green.

An Overnight Chlorine Loss Test might ease your concerns.

 

[reggiehammond]

My only comment is that a FC of 10-12 at CYA 50 is not bad. It gives you a ton of room for error (big pool party, kids peeing in pool, big rain, etc) and causes no detrimental effects. When you dial back the SWCG, go slow, as you don't want to end up on the other end of the spectrum.

 

[jmastron]

Thank you all. CYA is 50. SW Chlorinator is set at 4. I guess I can try throttling it back, or, as suggested, turn off the pump entirely. I agree TS that it is WEIRD. Never happened previously. How does a SW chlorinator keep the FC at ~ 11+? It's been a couple of days. Also, why/how am I getting a consistent CC of 0.5 - 1? That says something funky is living in the water to me, but what do I know?

The key is that an SWCG doesn't "keep" or "maintain" a chlorine level -- it generates new chlorine that gets added to whatever's already there. If it's generating more than is being consumed by sun/algae/etc, the FC will just keep rising. An RJ-45+ is spec'ed at 2.0 lbs/day of chlorine, which is a significant. Over 24 hours at 100%, it's basically like pouring *2* gallons of 12.5% Liquid Chlorine into the pool (plus or minus, and if you sat there and slowly dribbled it out throughout the day ). Scale that down to your actual runtime/24 hours (which I didn't see) and setting (40% I think you said?) to get an idea.