Cannot measure FC after Jack's Magic Copper stain treatment-ugh!!

[CatDr]

This is a long story and I will try to keep it as concise as possible. I have a 7 yr old aggregate 14140 inground pool. It has a SWG and a gas Pentair heater. It was maintained up until this July by 'professional' pool services. Both services managed to let the pool get stained. Per the Jacks Magic stain kit (done 3 times) it was copper staining, I would guess from not maintaining the pH and the copper gas heater core. I followed the instructions provided with Jack's Magic treatment #3 / #2 process. This was done July 16th, and honestly did very little. I contacted Jack's Magic and they were unfortunately not very helpful. I gave up for now and rebalanced the water.

The problem I have is typical from what I have read here: I cannot measure FC due to the stain removal products, everything reads as combined chlorine. My old SWG gave up the ghost just before the stain removal in July, and so I maintained the pool with liquid chlorine until the water was balanced, at which time I put a new CricuPool EDGE 40 on the pool.

I am having trouble with small algae growth at the corners of the pool. The water is clear.

My latest water testing (done at home with a TFT-100)
FC reads 0.5
CC reads 9.0 (again I have not been able to measure FC since adding Jack's Magic)
pH is 8.0 this afternoon (7.8 2 days ago)
TA 70
CH 250
CYA 50 (low I know but my chlorine does not seem to drop but rather is too high)
Salt 3000-dropping with LOTS of rain last few weeks-need to add some salt.
Temp 86 F

I have a Maytronics robot that I run 2x per week for 3 hours at a time.
I flush the filter once a month
The Pentair variable speed pump is set to filter the entire pool daily:: 2500rpm for 3 hrs, 1400rpm for 6 hrs, 750rpm for the remaining 15 hrs. (The math indicates filtering 45540 gal per day) This math is courtesy of 'Swimming Pool Steve' on YouTube who tested flow rates for the same Pentair variable speed pump I have.
The Circupool runs 24hrs a day set to 3/8-the low flow light never comes on even with the low flow of 750rpm.

So I have algae forming on the sides almost daily, is does brush off easily with the robot, or by pool brush. But it keeps forming daily. The water is clear. I am concerned I have high CC, and very little FC. But I cannot measure this reliably thanks to the Jack's Magic. ( for what it is worth, I took a water sample to Leslie's pool and they told me my FC was 0.34ppm and CC was 12.0ppm). Do I need to SLAM the pool? And how do I can I do this if I can't measure the FC? Jack's Magic is of little help--they do not seem to believe FC is important, just total chlorine.

Thank you for bearing with me--I am sooooo frustrated. This mess was created by the 'professionals.' This just shouldn't be this hard?!

 

[Texas Splash]

Doing an accurate SLAM at this time will be very difficult because of the lopsided FC-CC readings impacted by the Jack's. @JamesW is well-versed in explaining that situation, but I suspect it will take quite a while before the Jack-s gets eliminated to where you can start seeing reliable FC-CC readings again. But let's give James a chance to reply.

 

[JamesW]

Do an OCLT to get an idea how the chlorine is doing.

Keep inching it up until you pass the OCLT and then hold it there for a few days and then begin to lower it until the OCLT gets close to being failed.

If you can reliably pass the OCLT, the chlorine should be enough.

Brush every day or every other day.

Maybe consider doing a partial drain and refill or continuous dilution to get rid of the copper and the sulfamic acid.

Don't drain unless it is safe to do so without floating the pool.

The sulfamic can still react with the heater core and damage it, so the faster you can get rid of it the better.

 

[CatDr]

James,

Thanks for the reply.

So I measure the CC with the drop test at night and early in the morning? Do I turn off the SWG over night and see what the drop in CC is? You mention increasing the chlorine daily until I pass the OCLT--over the 9ppm I have now? And do I use liquid chlorine or turn up the SWG?

As to drain and fill--I live in SW Florida--lots of rain every day--what is the risk of floating my pool? I have read about using a pump in one end and the hose in the other. Any specific instructions on doing this. And how do I know how much water I am changing and when do I stop?

Thank you for your patience with my questions.

The heater is currently off and 'out of circulation'

 

[JamesW]

Do I turn off the SWG over night and see what the drop in CC is?

Yes. Check FC and CC to get the total and then do the OCLT on the total.

As to drain and fill--I live in SW Florida--lots of rain every day--what is the risk of floating my pool?

Risk is probably high.

Do you have water nearby?

If yes, at what level compared to the pool?

I have read about using a pump in one end and the hose in the other.

That will work.

You can use the salinity or CYA as a test to know how much water has been exchanged.

For example, if the salinity and CYA drop in half, then you have replaced half of the water.

I would replace 50 to 75%.

 

[CatDr]

Thank you

I will do the OCLT based on fc+Cc tonight
I’ll post the results tomorrow

Then I will begin to change the water
Would you advise I turn off the swg and use liquid chlorine while swapping water (salt is going to drop) or add salt as I go?

 

[JamesW]

Use liquid chlorine

 

[revitup]

I went through the exact same issue with testing chlorine after using that same stain removal treatment. I just left the SCG output and runtime the same as always and dumped in a 1.5 ppm liquid chlorine ‘kicker’ every day. Made it through without any water issue for the 36 days it took to begin registering FC again.

 

[CatDr]

So the results of my OCLT
Lasy night FC 0.5 CC 6
This morning FC 0.5 CC 6
So Nothing eating chlorine?
Is the test really valid using the TC?

 

[JamesW]

Is the test really valid using the TC?

Yes.

If you see algae, follow the SLAM procedure.

 

[CatDr]

Yes.

If you see algae, follow the SLAM procedure.

What is my criteria for the SLAM? When do I stop?
My water is clear and I am not losing chlorine. though I am only measuring 0.5 FC and high CC due to the stain removal chemical

I did add liquid chlorine 3ppm. Tested 30 minutes later and got a FC of 1.5 and a CC of 8. Looks like my FC is being converted to CC VERY FAST but not being used up

I read on another thread that my CC is actually N chlorosulfamate. And a poor sanitizer but not completely ineffective?

And I am waiting until this eventually degrades back to chlorine and sulfate?

Changing my water will speed up the process?

Do I understand this correctly?

 

[JamesW]

What is my criteria for the SLAM? When do I stop?

Standard criteria. No algae, water clear, pass OCLT.

I read on another thread that my CC is actually N chlorosulfamate.

Yes.

And I am waiting until this eventually degrades back to chlorine and sulfate?

Waiting for it to degrade.

Changing my water will speed up the process?

Yes.

 

[CatDr]

Thanks

If I see algae I use TC as my SLAM target? My TFP APP says FC of 20. I raise my TC to 20 and maintain until algae goes away. The. Let is settle back down?

 

[JoyfulNoise]

I not 100% convinced the SLAM will work properly. You can certainly try it out as @JamesW suggested but you have to realize that your primary “sanitizer” at this point is N-chlorosulfamate, not hypochlorous acid. Those are two very different sanitizers and algae could be less sensitive to the former. So there’s really very little factual guidance at this point, just guesses and trial & error. Chlorosulfamate at one point was proposed as a pool disinfectant but was found to lack the killing power that chlorine has and so it was mostly abandoned.

I would suggest the opposite course of action - get rid of the water. Do an exchange drain (there’s instructions for doing that in the TFP Wiki) and get as much of the contaminated water out of the pool as possible as safely as possible without floating the shell. Then you can reliably SLAM the pool.

 

[duraleigh]

The. Let is settle back down?

No. The SLAM process has a definitive end. Meet the three criteria found in the SLAM article.
1. Your Pool water is crystal clear with no visible sign of algae
2. You passed the OCLT losing not more than 1 ppm of FC
3. Your CC's test is either .5 ppm or 0 ppm.

Then you can let FC drift back down.

 

[ajw22]

Do an exchange drain (there’s instructions for doing that in the TFP Wiki) and get as much of the contaminated water out of the pool as possible as safely as possible without floating the shell.

Draining - Further Reading

www.troublefreepool.com

 

[CatDr]

More food for thought
I appreciate that there is no great answer here
Irony of all of this is the Jacks Magic did NOT fix the copper stains. And now I have a new mess
I’ll try the “SLAM” keeping TC at 20ppm and if needed swap the water
I need to research where to dump the water anyway. The City sewer May be best but not sure I’m allowed to do so
I’ll call next week to find out

 

[JamesW]

Do you have pictures?

Are you a cat doctor?

Do you have an opinion on this thread?

How likely are pets (cats) to suffer salt poisoning?

My cat's been drinking from the pool. I think she's doing it because the salinity is low right now (1400ppm). I just had an ominous conversation w/the vet about the danger of salt poisoning. She wouldn't commit to a safe level, so I'm having to play it safe by cutting it short. Tomorrow I'm...

www.troublefreepool.com

 

[CatDr]

Do you have pictures?

Are you a cat doctor?

Do you have an opinion on this thread?

How likely are pets (cats) to suffer salt poisoning?

My cat's been drinking from the pool. I think she's doing it because the salinity is low right now (1400ppm). I just had an ominous conversation w/the vet about the danger of salt poisoning. She wouldn't commit to a safe level, so I'm having to play it safe by cutting it short. Tomorrow I'm...

www.troublefreepool.com

I’ll get some pictures

And I left my thoughts on the other post there

 

[CatDr]

Update and a question

So if I keep the TC at 20 it is controlling the algae. I was gone for 3 days. TC slipped down a bit and some algae growth but clear water. Brushed and vaccines with the robot and added bleach and all good today.
FC 3.5
CC 17.5

BUT my pH is 7.2? My SWG is running and I have not added acid in the last week or so. What is driving down my pH and should I increase it back to 7.6?

Maybe I’m overthinking this. But I worry about low pH and the plaster and equipment

Thanks