Can’t generate enough Chlorine - thoughts.

[Candurin]

So, I just noticed my water had gotten a tinge cloudy 2 days ago. Not significantly, but, not TFP clear that we’ve been enjoying since opening.

Few notes, I have always had my IC40 set to 20% and it has always kept the FC between 4-7 reliably. We haven’t seen any rain and it has been 85 degrees and above with over 80% humidity for 10 days or so). We have also had 7-8 straight days of kids and adults swimming.

I immediately tested my water and noticed that it dropped down to 1 FC (0 CC and all other test parameters are within ideal range).

I ran to HD and grabbed 7.5% HDX bleach (all they had on the shelf) and added 2 gallons.
I just tested it this am and it was 2 FC.

CYA is good (70) and water looks clear.

I’ve been running the IC40 at 60% for 24 hours and not increasing the FC enough. I just now set it to 80% and I am running a super chlorinate cycle for an hour.

Any ideas at something I’m missing? We are expecting 5 days of rain (you know, because holiday weekend). After that time, I plan on tearing down my filter and reloading fresh DE since I’ll have to lower water and that seems to be a good time (we had a lot of pollen in the beginning when we opened and psi is increasing along with gpm throughput decreasing)

Just not getting enough FC it seems.

 

[mknauss]

Do an Overnight Chlorine Loss Test but it sounds to me you need to follow the SLAM Process. The SWCG is not designed to raise FC quickly enough to do the job. Do you have an Ocean States Job Lot store nearby?

 

[Mdragger88]

Algea is eating your chlorine so u must address that first w/ a SLAM Process
After passing all 3 end of slam criteria you can troubleshoot to see if your cell has an issue that allowed fc to fall below min for your cya FC/CYA Levels.

 

[Texas Splash]

Sounds like algae has already started from the heavy bather load and low FC. You can do an Overnight Chlorine Loss Test, but I suspect a SLAM Process is required.

 

[PoolGate]

20%? Is that running 24x7? I doubt that is running enough to create what you lose each day. Super Chlorinate btw just runs your SWG at 100% usually for 24 hours. Running "a super chlorinate cycle for an hour" does nothing but set it at 100% output.

 

[Candurin]

20%? Is that running 24x7? I doubt that is running enough to create what you lose each day. Super Chlorinate btw just runs your SWG at 100% usually for 24 hours. Running "a super chlorinate cycle for an hour" does nothing but set it at 100% output.

It’s 20% running 24/7 at the lowest flow rate that generates chlorine.

 

[Candurin]

Do an Overnight Chlorine Loss Test but it sounds to me you need to follow the SLAM Process. The SWCG is not designed to raise FC quickly enough to do the job. Do you have an Ocean States Job Lot store nearby?

No job lot in south Jersey, unfortunately. We do have an ace hardware with plenty of stock of 10% LC. I’ll head over there shortly.

The water is crystal clear at the moment. Any visual indication that something is wrong seems to be non-existent.

I guess my lesson learned is that I did not adjust the swcg output to a higher percentage in order to compensate for usage this past 2 weeks.

 

[PoolGate]

What chlorine number are you targeting? You should be targeting a "7", which is 10% of your CYA value. If you are trying to target the minimum chlorine level for your CYA level you are asking for trouble.

 

[Candurin]

I have been targeting 5 FC. Clearly, I need to move that up. I’m going to dump in some 10% fresh LC today and then conduct the overnight test. Of course, we will have 5 days of rain, so chemistry will be awry come Monday.

Kids are in now. Water is TFP clear, nothing in skimmer hairnet and robot filter (the fine mesh one) is clear too. Maybe I dodged a bullet with the algae, but, I’ll hold my judgement until I confirm with the tests.

 

[Candurin]

We shall see what happens in the morning. Shut down SWCG at 8:00 took water sample at 8:30pm. I plan on taking sample around 6:30-7am before sun hits the side yard.

FC was at 7 when I tested it with 0 CC. All other tests were spot on as well. Water is crystal clear, albeit a bit warm (92 degrees).

 

[huggies]

When's the last time you checked your CYA? Maybe low, causing extreme sun loss. Or too high causing your CL to be ineffective.

 

[Candurin]

Just checked CYA yesterday. It’s at 70.

I need to SLAM. FC down to 4, from 7 last night. I’ll keep everyone posted.

 

[Mdragger88]

 

[Candurin]

It has been started. Should be easy enough as we will, unfortunately, have a few days of no swimming. Right now the FC is at 19 ppm and I just added another 11 ppm, bringing it to 30, just a few higher than the chart. I’ll use the SWCG generator to keep it above 28ppm. I also have a backup gallon of 10% LC.

I’ll also take the time to strip down and clean my filter and refresh the DE after the few days of thunderstorms. Might as well make the most of this. I even magic erased the entire inside of the skimmer (eww). Even with hairnets, that was nasty.

 

[reggiehammond]

It has been started. Should be easy enough as we will, unfortunately, have a few days of no swimming. Right now the FC is at 19 ppm and I just added another 11 ppm, bringing it to 30, just a few higher than the chart. I’ll use the SWCG generator to keep it above 28ppm. I also have a backup gallon of 10% LC.

I’ll also take the time to strip down and clean my filter and refresh the DE after the few days of thunderstorms. Might as well make the most of this. I even magic erased the entire inside of the skimmer (eww). Even with hairnets, that was nasty.

You mention no swimming - you can safely swim during a SLAM, there's no reason to avoid it if only because of the SLAM.
I'd make sure to test after swimming to bring FC up after the bather load consumes FC.

 

[Candurin]

No swimming because of the rain, not because of SLAM

I should have made that statement more direct, sorry.

 

[revitup]

The SWCG will likely not help hold your FC at slam level. Typically the SWCG should be off for the SLAM. Use liquid chlorine only.

 

[Candurin]

Seems like I am done SLAMming. Pool is crystal clear, CC is 0 (CC has always been 0 though), and FC stayed at 27 (54 drops) last night and again this morning.

Today, I am going to backwash and fully clean filter and then we should be good to go.

Any suggestions when to turn SWCG back on? Should I turn it back on at 7 FC or around 10? I plan on keeping it around 7 for now on.

 

[revitup]

8 to 10 is a nice range to hold your FC. I use 7 as my minimum and don’t have any problem letting it drift up to 11 or 12.

 

[Candurin]

Sounds like a plan!

Just got done stripping down filter and cleaning it out. Was quite easy and done in under an hour. Now my pump is dialed down to 1600 rpm to generate chlorine (we run it 24-7). Getting 16 GPM and using 201 watts.