Intellichlor not generating chlorine. Salt sensor issue?

[MostlyCanuck]

Hi folks - hope this finds you all well.
My pool has been on autopilot for a while till last week when I realized the SWG (IC60) wasn’t producing chlorine.
I’ve been getting FC readings of/near zero for a week+. Water is perfectly balanced. No CC or algae. SWG cell “looks” perfect - all green lights and when the cell light is on I even see some bubbles at time indicating it’s operative. However, no chlorine in the pool (even keeping the IC60 at 60%+ which is way oversized for my pool and pump running 24/7).
Totally buffed.
The only thing I noticed is that since a month ago the salt reading on the intellicenter wall unit has been slowly going down (now at 3000) but two separate tests (Taylor and strips) confirm it’s still 3600ppm. So this suggests to me there’s something wrong with salt sensor (on intellicenter or intellichlor?) and perhaps this is preventing chlorine generation? The SWG is not indicating low salt.
The cell itself is new - installed last year - which makes me think it’s the intellicenter perhaps?

Such a mistery I’m at a loss.. any suggestion?

 

[an1vrsy]

I’ve been getting FC readings of/near zero for a week+.

You may want to bump up your FC to high target then do an OCLT. If successful hitch eliminates algae, then do an overnight chlorine *gain* test.

Test FC after the sun has gone down, set your IC60 to 100% then check again in the morning before sunrise. If FC is higher, you can calculate how much was gained.

 

[MostlyCanuck]

You may want to bump up your FC to high target then do an OCLT. If successful hitch eliminates algae, then do an overnight chlorine *gain* test.

Test FC after the sun has gone down, set your IC60 to 100% then check again in the morning before sunrise. If FC is higher, you can calculate how much was gained.

I have it running on pucks now just to keep it chlorinated - will take those off and do another oclt as you suggest just in case but first one indicated no algae…

Any idea what might be going on with the tech? Clearly something is wrong with the salt readings and it may or may not be a coincidence…

 

[Jimrahbe]

MC,

I have yet to see an IntelliChlor, with an operating 'Cell' light, that was not making chlorine.

Set your cell's output to 50% and watch the Cell light.. It should come on for about 2.5 minutes, when the cell is making chlorine, and then it will be off for about 2.5 minutes, while the cell is at rest. If that test passes, the cell should be making chlorine.

I suggest that you perform an Overnight Chlorine Loss Test.. (OCLT) You will need to add enough Liquid Chlorine to get your FC up to 8 to 10 ppm before starting the test.

The salt reading has nothing to do with your problem.

Thanks,

Jim R.

 

[an1vrsy]

The salinity test the cell does has an accuracy of +/- 500.

 

[MostlyCanuck]

Thx folks. I might be blaming the tech when the fault is me perhaps. Will slam / oclt to rule that out

 

[MostlyCanuck]

@Jimrahbe @an1vrsy I have to thank you both for bringing me back to reality. You were right and I was wrong - the Intellichlor works just fine after I slammed the heck of out my pool for 3 days in a row. Clearly I had a just enough invisible algae that the cell could not keep up without a clean start - and I think it happened as I was on vacation when it looks like I had a power failure and the cell was off for a couple days - likely enough to let algae start growing.

I find every time that I keep the Intellichlor at or just above target FC levels, something always happens that eventually it dips down and algae sets in (power off, weather changes with unexpected sun/heat, etc).... and instead I find that it would be far easier to set the Intellichlor a fair bit higher than target so that there's always a significant buffer. Based on what I've read, there is no issues with health or equipment damage from doing so (we're talking keeping it at , say, 10-13 FC instead of 7-8 FC, not massively more).. am I right? is there a downside except from using up the cell more than you need to (efficiency)?

Thx again!

 

[Newdude]

is there a downside except from using up the cell more than you need to (efficiency)?

Nope. And you really don't use much extra cell life. Once you've raised the level, your mostly maintaining the same way you were. The difference in burnoff between the two levels is negligible for the benefits it provides. Yes, the higher FC burns off quicker, but not quicker enough that you'll care.

What's the current CYA level ? Many of us get alerted that our CYA level has dipped, or wasn't raised to match the latest UV increase, when we notice the FC isn't holding. If we don't notice it quick enough, we have a low CYA problem, *and* algae.

With a passed OCLT, if you're losing more than 4 fc a day (or so), you need more CYA for that point in the season.

 

[an1vrsy]

we're talking keeping it at , say, 10-13 FC instead of 7-8 FC, not massively more).. am I right? is there a downside

If you are going to be at FC 10 or higher consistently, then keep in mind pH test is not accurate. You will either have to invest in a digital pH meter or wait to test pH when FC gets below 10.

 

[MostlyCanuck]

Nope. And you really don't use much extra cell life. Once you've raised the level, your mostly maintaining the same way you were. The difference in burnoff between the two levels is negligible for the benefits it provides. Yes, the higher FC burns off quicker, but not quicker enough that you'll care.

What's the current CYA level ? Many of us get alerted that our CYA level has dipped, or wasn't raised to match the latest UV increase, when we notice the FC isn't holding. If we don't notice it quick enough, we have a low CYA problem, *and* algae.

With a passed OCLT, if you're losing more than 4 fc a day (or so), you need more CYA for that point in the season.

thx for confirming that! sounds like a good strategy indeed to keep a solid buffer!

interesting you mention CYA - I've always kept it within range but for some reason this year I've been struggling with it. I kept on adding more of it and it kept on dropping. first I thought the reagent wasn't testing right so I bought a new bottle - that wasn't it. I wonder if my granules, that I bough last season (they're >1yr old and have been stored in a bin outside over freezing winter) have deteriorated in potency... it's been raining/draining a fair bit but not as much to justify the drop in CYA (if anything this has been a drier season so far I think).

Do you think the dry CYA granules can deteriorate like that?

 

[MostlyCanuck]

If you are going to be at FC 10 or higher consistently, then keep in mind pH test is not accurate. You will either have to invest in a digital pH meter or wait to test pH when FC gets below 10.

thx for the reminder. I had forgotten about that but now I recall reading this, yes.

so far my testing seems to have been accurate - and I can manage it through MA as expected - by testing before/after additions.. when you say it's not accurate above 10 FC, is that by a very large margin? with ph I don't think it really matters if it's +/- a few points as long as you're in that 7.2/7.8 range / in the 7s... so if you test in mid-range and it's off by a small margin that's no big deal.

I don't mind investing in a digital ph meter, but all the reviews I read seem to suggest that they aren't always that accurate and require constant recalibration with ph solution... do you have any recommendation for one that's better and not as needy of maintenance?

 

[Ahultin]

do you have any recommendation for one that's better and not as needy of maintenance?

I use the apera ph60 and calibrate it about every 4-6 months. About once a month (and when fc is <10 ) I use the phenol red test and compare results . I am happy with the results and consistency.