Salt pool chlorine generator (IC40) not working?

MarkBee123

Member
Oct 29, 2018
15
Oakland
Hey everyone,
So as a new pool owner on a property that we share with friends, so I am only up on the weekends, this last weekend the pool was cloudy and chlorine levels low. After a bit of research I realized I had let the total Alkalinity get way too high ~240 ppm. I cleaned the chlorine generator (IC40) with muriatic acid and it had significant calcium build up. So now we are in the process of adding acid, aerating, rinse, repeat to get the still high alkalinity down. The pool is mostly covered and the IC40 is on full (5 LEDs) for the last 4 days and still almost no free chlorine. We are only running the pumps about 6 hours per day, the pool is fiberglass 22000 gallons. The cyanuric acid is a little low, about 40 ppm, will be fixing that this weekend. I am concerned that the free chlorine doesn't come up at all... or even show if I dunk a test strip right into the return jets which I would think should read high...
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
23,669
Laughlin, NV
First. Test strips are junk. Get a proper test kit - Test Kits Compared. I suggest the TF100.

You need to raise your FC with liquid chlorine to get into target range based on your CYA - see FC/CYA Chart

Then, your SWCG must create enough FC each day to replace that lost to UV and organics. Typical loss during swim season is 2-4ppm. So start at 4 ppm each day. In your pool volume, from Poolmath, you need to run the pump 14 hours per day with the IC40 set at 100% to create that amount of FC.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
15,866
Bedford, TX
Mark,

Your pool is cloudy because you let your FC level get way too low, TA has nothing to do with it.

SWCG's are designed to maintain an FC level, they can never keep up with an algae bloom.. Just because you can't see green does not mean you don't have algae.

If I had your pool, the first thing I would do is an Overnight Chlorine Loss Test (OCLT)... Overnight Chlorine Loss Test

This test sees if you have an FC loss overnight.. If you do it means you have algae and need to perform a SLAM... SLAM Process

As far as the IC40.. if the green "Cell" light is on, then most likely the cell is operating just fine.

Thanks,

Jim R.
 

MarkBee123

Member
Oct 29, 2018
15
Oakland
Ok, so based on everyone's comments, I need to SLAM, assuming the CYA is 60 or less I need 24ppm free chlorine and run the pump 24/7 that means 4 gallons of chlorinator (2x strength Bleach) so I'll have my freinds who live up there do that tonight. I cleaned the filters (the pressure was fine, but wanted do anyway) we get a lot of organic stuff in the pool, dirt, leaves, grass, bugs.. I am pretty sure we have been running lowish FC for quite a while. After the SLAM then we can do an OLCT. We want to be able to swim this weekend so if we SLAM tonight, assuming there are a lot of organics will 2 days be enough time for the FC to be swimable? I know that it's really not "knowable" without knowing all the parameters, but it that a reasonable assumption?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
23,669
Laughlin, NV
You can safely swim in a pool as long as the FC is above the minimum and at or below SLAM level based on your CYA. You must also be able to see the bottom of the pool in the deep end of the pool.
 

MarkBee123

Member
Oct 29, 2018
15
Oakland
You can safely swim in a pool as long as the FC is above the minimum and at or below SLAM level based on your CYA. You must also be able to see the bottom of the pool in the deep end of the pool.
Ok thank you. Can definitely see the pool bottom at the deep end. I understand the SLAM is a process, still reading too. I guess I am just concerned about swimming if the FC is over 15ppm, but sounds like that is just fine. All the lights are green on the IC40.
 

MarkBee123

Member
Oct 29, 2018
15
Oakland
quick update, the group wasn't exited about SLAMing the pool over weekend so we added chlorine to over 5ppm two nights in a row and the chlorine level is around 3-5 this morning, with 3 hours of generator on from midnight to 3am, if we manage to not drink too much wine tonight we'll do a formal overnight chlorine test and SLAM starting Monday if needed. Seems like high alkalinity isn't a dramatic problem, but still quite high at 200 ppm (taylor liquid titration) but I will continue to add muriatic acid and aerate until those levels are lower. CYA is now around 65 ppm (taylor turbidity test) will bring that up another 5-10 ppm. Thank you everyone for you excellent advice, will update as things progress. Also, I cleaned the filters well before the pressure level was much higher than when they started, but the were quite dirty (to my thinking) this makes me think annual cleaning is perhaps a better regime than waiting until the pressure rises.