Extremely high combined chlorine

[rmb212]

Thank you in advanced for all the info this site and members provide!

A couple of weeks ago I started noticing the water was a little cloudy (could still see bottom) and there was a small amount of green algae around the skimmer, light and border tile. I didn't want this problem to grow so I decided to get ahead of it with pool season only a few months away. In addition the SWG keeps showing low salt despite the salt test showing within range, not sure if they're two separate issues or not. My pool is a small fiberglass saltwater pool at 6k gal. The FAS/ DPD test initially showed FC at 1ppm and extremely high CC at 25 ppm. Other readings are in range or really close, TA 60, CH 250, CYA 50, salt 3800. After research, I decided to SLAM the pool and maintain a shock level to get rid of the CC.

I did do a Jacks Magic iron scale treatment with #1 and #2 products mid November, followed step by step and worked great at removing the stains I had on the pool. When I did start re-chlorinating I only turned the SWG back on which I am still learning and realize now I probably never got the FC up high enough with just the SWG. I am also unsure if the stains were metal, scaling or unknown but the combo of the #1 and #2 were the only thing that would lift them.

I'm on day three of SLAM and I've been using liquid chlorine and maintaining around 20-22ppm FC, checking 2-3 times a day however the CC continues to rise and is now closer to 30ppm. Also my FC is being consumed each time I've checked it dropped from 20 to 4-5, although it only dropped to 11 from last night to this morning.

I spoke to Jacks Magic rep and he says this wouldn't cause the high CC after this much time. Should I trust his advice and the test and stay the course? Should I replace the water? Any advice is greatly appreciated.

 

[ajw22]

Jack's Magic #2 Copper and Scale Stuff is sulfamic acid, which combines with chlorine to create CC.

Acid - Further Reading

www.troublefreepool.com

What model SWG are we discussing?

Draining a fiberglass pool is always a risk. Consider doing a No Drain Water Exchange …

Draining - Further Reading

www.troublefreepool.com

 

[rmb212]

Yes water would have to be exchanged if it comes to that, I wouldn’t risk draining. SWG is Solax pure chlor, I believe the model is CLG132A-020 but need to confirm that.

 

[JoyfulNoise]

The scale remover is causing your problems. Chlorine reacts with sulfamic acid to continuously form N-chlorosulfamates. Those compounds show up as CCs on a chlorine test. It will take weeks for chlorine to oxidize all the chlorosulfamates to nitrates and sulfates.

Definitely consider the no-drain water exchange.

 

[rmb212]

It’s been over 90 days since that treatment, would it still affect CC at this point? Rep seemed confident that after that amount of time it wouldn’t affect CC. Pool stays uncovered and running through winter.

SWG data is correct and off during SLAM Process. Also using TF-100 test kit

 

[rmb212]

Or are you saying it would take weeks for it to oxidize using SLAM give I prob never got the FC to where it should of been after treatment?

 

[JoyfulNoise]

It’s been over 90 days since that treatment, would it still affect CC at this point? Rep seemed confident that after that amount of time it wouldn’t affect CC. Pool stays uncovered and running through winter.

SWG data is correct and off during SLAM Process. Also using TF-100 test kit

Or are you saying it would take weeks for it to oxidize using SLAM give I prob never got the FC to where it should of been after treatment?

You can’t easily get to SLAM levels of FC when sulfamates are present. The sulfamate completely uses up the available chlorine and converts most of it to chlorosulfamate. The equilibrium is such that the chlorosulfamate is the dominant species at pool pH values. So then you’re simply left with hydrolysis of the chlorosulfamate into chloride, nitrogen/nitrate, and sulfate. The hydrolysis process is slow even under favorable conditions and extremely slow when water temperatures are cold.

You can continue to run your SWG but, until you see the CCs start to break and go lower, you’re still battling the scale remover. There are many threads on TFP documenting the difficulties people have with the Jacks #2 scale and stain remover.

 

[rmb212]

That makes sense, would the sulfamate explain the little bit of algae? I think it’s time I cut my loses and exchange the water.

This all started due to a mess up of the paver guys. They poured the coping base too high and had to grind it down which resulted in a bunch of concrete dust in the pool and caused the staining. Brand new pool with dirty looking walls, can’t live with it. I did try advice from here by lowering ph and scrubbing everyday for about a week but didn’t touch it. Been a bit of a pia, and not pumped on this from jacks magic, however it did clear it up over night, so be it, live and learn.

 

[rmb212]

Also thank you for taking time to give me advice

 

[ajw22]

That makes sense, would the sulfamate explain the little bit of algae?

The low FC let the algae take hold. If you had maintained an adequate FC level with the sulfamate you would be fine.

Acid - Further Reading explains how to test FC after using sulfmanic acid.

Low FC for your CYA level is never good - FC/CYA Levels

 

[JoyfulNoise]

@ajw22 - note, you can’t maintain adequate FC when sulfamate is present. The sulfamate concentration from the stain protocol is roughly 10lbs per 10,000 gallons of pool water or roughly 120ppm of sulfamate. It would take over 88ppm worth of FC addition to fully react with that much sulfamate before the FC starts to register (you'd see some FC register before then because the equilibrium would all for it but it will be quite low). If there's any CYA in the water, all that FC is going to get bound up making the process even slower. Chlorosulfamate is a slow disinfectant but it doesn't breakdown right away when it disinfects - it converts the chlorine it has to chloride (killing the pathogen or oxidizing something) and the sulfamate part goes back into solution to scavenge more chlorine. It's only when the sulfamate is hydrolyzed that it begins to breakdown on its own. That process is very slow and is why no one ever really gets a good measurable FC. You simply can't add enough chlorine to the water ... well, you could, but it would be scary as heck because you might as well backup a Clorox tanker truck to your pool and start dumping it in.

@rmb212 - the algae likely formed because chlorosulfamate is a very slow sanitizer and the excess sulfamate in the water was simply scavenging all the chlorine. Once the sulfamates are added, you're in for a world of trouble which is why TFP always suggests that if you need to remove copper stains, then you can add the Jack's #2 but you’re better off just draining the pool after the stains are lifted rather than fight with the sulfamate-poisoning of the water. I know the Jack's Magic protocol says that it's "ok" to have the high CC readings and that they will eventually go away, but I think they are way too optimistic about that as it takes a long time and most pool owners don't have that kind of time to waste. It's a really a darned-if-you-do / darned-if-you-don't situation ...

 

[rmb212]

It really al makes sense when broken down on a chemical level. After exchanging water is there a sequence on which chemicals to start rebalancing, perhaps a link exist on here you could point me too.

Also, would it be a good idea to put a filter on the fill hose? If so, any recommendations. Given all the stuff I've fought through on this I'd really like to get it right on this time around and keep it that way now were way out of the construction phase.

 

[ajw22]

Iron Fill Water Filter - Further Reading

www.troublefreepool.com

Add 5 ppm of FC daily so you don’t get algae again.

 

[JoyfulNoise]

It really al makes sense when broken down on a chemical level. After exchanging water is there a sequence on which chemicals to start rebalancing, perhaps a link exist on here you could point me too.

Also, would it be a good idea to put a filter on the fill hose? If so, any recommendations. Given all the stuff I've fought through on this I'd really like to get it right on this time around and keep it that way now were way out of the construction phase.

No specific order other than maintaining proper FC/CYA levels is key. You want to keep the water sanitary.

There are no “hose end” filters that will do anything useful for you. They can barely treat a few hundred gallons of water at best and so there’s no point in wasting money on them.

Since this would be an exchange drain where you’re trying to keep the water level the same the entire time, I would simply put a blue plastic chemical floater or two in the pool each filled with trichlor pucks. They will add both FC and CYA to water as it is exchanging. Then, when you feel you’ve flushed out enough of the contaminated water, you can run the pumps and get everything circulating. Then do some testing to get a baseline. Once you’ve got that, report back and we’ll help you out.

 

[rmb212]

Ok, will do thank you

 

[rmb212]

So started water exchange today and rounded up the the basics to rebalance, baking soda, salt and calcium chloride (already have 3 gal liquid chlorine and some cya on hand). Gonna take a few days I'm moving at about 200 gal per hour. I couldn't find any trichlor pucks that I trusted with out spending 70 dollars at the pool store.

Guy at the pool store said not to put any CH in a fiberglass pool, but I do not trust that he is correct. Says on pool math I should be 350-550 ppm. The CH increaser I got is Sparco Calcium Plus looked for an SDS on that and couldn't find anything concrete, I have access to MSDS online for any chemical at my office but I wont be back there till Monday. Do you recommend using that product for CH and what level should I be at when it comes time to rebalance?

 

[mknauss]

If you do NOT have a waterline tile with cement based grout, then you do NOT need Calcium in your fiberglass pool.

 

[JoyfulNoise]

Fill your pool up first and then measure the CH and all the other chemical levels. Then we can have a conversation about what you should do. There is no danger in having low calcium hardness water in a fiberglass pool for a few days. It’s not going to turn into a black hole and suck the entire universe into it.

Just put down the CH increaser and back away from the package slowly …

 

[rmb212]

I have a waterline tile with which I'm pretty sure is a an epoxy grout.

 

[mknauss]

I have a waterline tile with which I'm pretty sure is a an epoxy grout.

If true epoxy, you likely only need a low level of CH to prevent foaming. Your signature does not show a heater. If you have a gas fired heater, you may need a bit more calcium.