High CC

[Summer424]

Intex pool, 1185 gallon. SWG. Just set it up and filled it a week ago. Levels have been great. I’ve had to top off with fresh water because of splash out, but tested after and all good. Now, Pool is clear, but now I’m dealing with these numbers with TF-100 kit and TF salt test kit:

Salt: 2400 (need to increase this a bit but swg manual says I should still be generating chlorine)
Ph: 7.5
FC: .5
CC: 1.5
TA: 50
CYA: I have never been able to detect CYA. Did first test hours after CYA dissolved (using sock method) and again today because I read it might take a few days to show up on test. Both times the solution was entirely clear. Never clouded, so black dot was always easily visible.

These levels are from after I ran SWG for the recommended 2 hours today. I took out the cell and cleaned it per mfg instructions (soak in vinegar and rinse) and ran SWG another 2 hours. Tested again. Same readings. I suspect, though, that CC went down a little because liquid was SO light pink after second drop. Barely noticeable tint of color.

Should I run SWG overnight on the system’s boost mode and see if that clears things up? Any ideas of what’s happening so I can prevent this in the future? I’m not doing anything different than I did last year and didn’t have this issue.

Thanks!

 

[HermanTX]

Are you sure your SWCG is producing chlorine? Just because the manual says it should does not mean it is at your stated salt level. You do not say what type of SWCG you have. Does it have a light on that says it is generating FC?

With very low CYA, your SWCG may not be able to keep up. Best to use liquid chlorine to quickly boost your FC level, then set your SWCG to maintain. The maintain part should be to replace what you lose each day due to UV and bather load.

Suggest you test your CYA again. How much stabilizer did you add? Are you using PoolMath app to calculate effects of adding chemicals?

Having a CC of 1.5 indicates something other than UV is consuming your FC but you need to get your CYA up to 30-40 and test all again. You may need to read SLAM Process to prepare if your CC stays above 0.5ppm

 

[Summer424]

Thanks, Herman. My SWCG is the Intrx Saltwater System model CS3110. It has a “working” light that’s on when it’s generating chlorine. I have not gotten the error code saying the salt is too low, so no indication from the machine that there’s an issue. I was planning to add more salt soon to get it up to 3000 because of splash out.

I added 1.6 oz CYA (dry acid) at start up. That’s what the swcg manual suggests, so I started with that. I do use pool math, but since I’m not getting any clouding on the CYA test, I wonder if something else is amiss (maybe with the test chemicals, or the dry acid), and wasn’t sure if it was wise to just add more. I just retested at your suggestion, and it’s the same. No clouding. Black dot easily visible when filled to the top. I’m new to the test, bit did the whole procedure recommended here-back to sun, held at waist height, glance.

I don’t have bleach on hand and won’t be able to get any today. Any suggestions on what I can do in the interim? Get more salt in there? Keep running the swcg? And how much bleach should go in to quickly raise FC to see if swcg maintains it once I get the level up? Just follow pool math for that?

Thanks so much.

 

[Rancho Cost-a-Lotta]

Intex pool, 1185 gallon.

Can you confirm the volume of 1,185 gallons?

 

[Rancho Cost-a-Lotta]

I added 1.6 oz CYA (dry acid) at start up.

Just caught this. Dry acid is sodium bisulfate which is used to reduce pH. Is this what you added with the intent to raise CYA? No harm done, if so.

CYA is cyanuric acid, most commonly marketed at "chlorine stabilizer." You can find it at Wal-Mart, HD, Lowes. This is a pretty good bargain for a 4-pound bag:



Don't use dry acid, even to lower pH, as it adds sulfates to the pool that can damage metals. This is particularly worrisome with the rare metals in the SWG.

 

[Summer424]

Mike, yes, that’s the volume: 1,185 gallons.

I added 1.6 oz of the chlorine stabilizer. I used exactly what you posted-the Clorox brand. My use of the term dry acid was a mistake. I meant to say it was granules, not liquid.

Thanks for the information on dry acid with SWG. I’ve used it to lower ph. Only once or twice in the last year. I won’t do that again!

 

[jeffchap]

1.6 oz of stabilizer would only raise your CYA by 10 ppm. This won't even register on the test. You need to add another 3.2 oz to raise it to 30.

 

[Rancho Cost-a-Lotta]

If my research on your SWG is accurate, it generates 4 grams of chlorine gas per hour. That equates to 3.4 oz per day, which should increase FC by 21 ppm per day (24 hours @ 100%).

1.6 oz of chlorine stabilizer will only increase CYA by 10 ppm, which you won't be able to see on the test. Add 4.7 oz to increase CYA by 30. You should see a net result of 40 ppm on the test. You can bump it to a higher level later:



You should be seeing an increase in FC with your SWG running. If not, there is either organics consuming chlorine (your CC level hints at this) or your SWG is not performing per manufacturer's claim. Run the SWG overnight and see what happens in the am. You should complete an Overnight Chlorine Loss Test tomorrow night when you get FC up to target level.

...Jeff just posted the same screen as I was typing...

 

[jeffchap]

All the Intex SWGs I've owned have had a clear tube that held the plates. When it kicked on, you could see bubbles forming on the plates. If you can see the plates and they are forming bubbles, it's working.

 

[Summer424]

Thanks so much, Jeff and Mike. I didn’t check cya and salt on pool math since the manual had specific directions on that. That’s a huge difference. I’m adding the additional cya. Not sure why the manual lists such a low start up amount. I must be missing something.

Do I test FC/Cc in the morning and follow pool math to get FC up with liquid chlorine (assuming things aren’t at the right levels)? Am I aiming for 4 FC at this point if I’m going to see if the SWG is able to maintain?

Thanks, Jeff, for the bubbles and plate description. I’ll take a look.

 

[Rancho Cost-a-Lotta]

Yes. That's a good plan.

 

[Summer424]

Thanks so much for the help everyone! Here's what happened:

SWCG ran last night until about midnight, and then back on today for three hours. It's still running. (Intended it to go through the night, but because of human error, it didn't.) Here are the test results as of now:

FC: 2
CC: 0
Ph: 6.8
TA: between 40 and 50 (at 40 it changes to a really light gray/pink, at 50 it's that deep pink that I think is what the directions mean by "red")
CYA is 30

Didn't retest salt since there was no splash out, so I assume it's still 2400.

I didn't add bleach/liquid chlorine as of yet, as things seem to be moving in the right direction. Should I go ahead and treat this as "normal" and follow pool math to get Ph up a bit? I added CYA yesterday and it all *seems* to be dissolved, but from reading it seems like it might take a day or two to see the full results on test. So, maybe test tomorrow and follow pool math to get CYA up to 40 if it's not yet there. Does that seem like a good plan? Better ways to approach this?

 

[Rancho Cost-a-Lotta]

Assume your CYA is 40 and add liquid chlorine to target level. Sun will continue to burn off FC during the day and your SWG does not seem as though it can keep up. Your SWG should be able to add ~.875 ppm of FC per hour. Either your SWG is under-performing or there are organics eating up your chlorine. Either way, you need to bump FC above minimum for your CYA level (FC/CYA Levels).

For the TA test, continue to add drops until there is no further color change. Don't count the last drop that resulted in no change. You may see variations in the shades of red, but the endpoint is the last drop that changed the shade.

Your pH and TA may be too low, but retest TA before we take action.

 

[Rancho Cost-a-Lotta]

I forgot to mention in the last post, but you do need to complete an Overnight Chlorine Loss Test tonight. If you fail, plan a SLAM Process or replace all water and start over.

 

[jeffchap]

Go ahead and add some salt to get back to 3000 ppm. You're a little low. If you have a lot of splashout, use 3200 instead.

 

[Summer424]

Ah, thanks for that information on adding drops for TA test until there is no color change.

FC: 2.5
CC: 0
TA: 50
Ph 6.8

 

[Rancho Cost-a-Lotta]

TA is okay, but pH is low. Do you have any Borax laying around? If so, add about 7 oz to increase pH to 7.4. Your TA will increase by ~12 ppm.

 

[Summer424]

I don’t have borax, but I do have baking soda.

 

[Rancho Cost-a-Lotta]

Baking soda will not move pH much. No hurry, but you do want to increase pH before swimming. You might try aeration (lots of bubbles and agitation) to increase pH. It may come up a bit naturally.

Big night tonight? Overnight Chlorine Loss Test?

 

[Summer424]

Ha! Yep. My first OCLT. No chlorine loss. But here's the thing: I got FC up to 3 as per OCLT direction minimum, but not all the way up to FC/CYA target level. (I bought household bleach, and when I went to add it last night to get chlorine up to the target, I noticed in the swcg manual that I should use a chemical based on Trichloro-s-triazinetrione or sodium dichloro-s-triazinetrione dihydrate instead, so I didn't end up adding it. Not my finest work--purchasing before reading--but that's what happened.) So, last night after sundown I had FC at 3 and CC at .5. Bright and early today, the results were exactly the same. That's good, right? Do I need to get the FC up to target and do OCLT again? Please say no!

I suspect that cleaning the salt cell has helped and things are on track, but maybe the slow rise in chlorine yesterday means I'm off base. It's a little strange that ph is low. It's usually fine because of the swcg.

Is this a reasonable plan?

1) Raise ph.
2) Use SWCG today to get FC up to target and keep it there. (Since there's no chlorine loss, should I still add chlorine at this point? Headed out today to try and find correct product.)
4) Add salt
4) Test CYA and increase to target, if needed.

Can pool be used today if ph and FC are at target levels?