SWG Troubleshooting

[benbuzbee]

So I have an 8133 gallon saltwater pool in Florida with a Pentair IC-30 SWG (rated for 30k gallons).
The whole pool and equipment are quite new, about 4 months old.
The pump runs for 12 hours at 55 GPM (so it should filter the entire volume 4-5 times) .

Things have been going ok, but I am having trouble now with the SWG

For the first few months we had the SWG set to about 50% and my Taylor Kit was constantly reading pretty high amounts of Chlorine - 5-6 PPM, things looked good and I was in the process of experimenting with dialing it down.

BUT! About a month ago, I registered 0 PPM, which is backed up by Pinch-A-Penny, so I went to check the SWG and it said we needed salt. Salt was at 2800 PPM, so we added 40.8 Lbs which should bring us to about 3400.

That did not seem to solve the problem. Currently, the SWG is at 70% and all lights are green, but I still read 0 PPM.

I suspect it isn't working, but I don't really know what to troubleshoot next. Are there any tests or things I should check before I go to my pool installer and claim it's broken? Is there anyway to prove it to them?

60PPM Stabilizer, supplementing with solid Chlorine in the meantime

Thank you!!

 

[JohnT]

Take a water sample by collecting right at the return with the SWCG set to 100%. Test that sample for chlorine.

 

[Rancho Cost-a-Lotta]

Which test kit are you using?

You should probably do an Overnight Chlorine Loss Test to rule out algae.

See this Wiki article for help with your SWG...

Pentair Intellichlor ICXX SWG - Further Reading

 

[Jimrahbe]

Ben,

I doubt there is anything wrong with your salt cell.. You let the salt level drop so low that the cell shut off and your FC went to zero.. That did not happen overnight, it took a while..

Now you have algae, even if you can't see it yet.. Even low level Algae can consume more FC than your cell can make..

That said, I have been wrong many times before, so you just need to run a quick Overnight Chlorine Loss Test (OCLT) and prove me wrong...

Overnight Chlorine Loss Test

Thanks,

Jim R.

 

[benbuzbee]

Thank you everyone for the education!

I am 100% sure it is Algae and have begun SLAM

I had no idea that is how Algae would present, or I would have caught this a long time ago. I also didn't expect the salt levels to drop that quickly or totally disable the SWG, so I learned a lot.

The internet is amazing

 

[benbuzbee]

Hey I'm back...

So I completely SLAM; it passed the OCLT; I cleaned the filter (green!); then set the SWG for 50%
This was like 7/24, read 4.0 PPM FC.
I added stabilizer (maybe too much? I Followed the app's recommendation but accidentally got up to 100cya or so) and
On 7/25 it was at 7.5 PPM FC from just the SWG and I thought I was good to go
7/28 read 5.0, figured it was just getting back to normal equilibrium
7/31 0.0 (oh Darnz)

I shocked it with some cal-hypo up to 5.0 PPM last night but by morning it was down to 3.0 (maybe an hour after sunrise...)
By the evening it was back down to 1.0 PPM.

So, I guess I need to SLAM it again?

Did I abort the process too soon? It seemed pretty promising, FC was going up and mostly stabilizing at high numbers. But