I am seeing CC at 3 in my spa

Oct 10, 2011
140
I have been trying to get the TA down in the spa since the Ph was rising to 8.2 when aeration was in use. The TA had gone to 110 so i lowered it to 50 with dry acid and that seemed to correct the issue. I also needed to add stabalizer to the tub as it had slipped to 18 from adding water periodically I guess. Have the CYA up to 35 now and when I check my CC it is at 3. Do I simply shock the tub to 12 and keep it at that level for a period of time? How long? Is this normal? Thanks for any pointers. Jim
 
Keep in mind that CC in a hot tub is VERY commonly seen in the hours after a soak. It takes a while for chlorine to oxidize the bather waste. The time to check for CC is 24 hours after a soak or just before your next soak. That's when the CC should be low (<= 0.5 ppm). Nevertheless, if you see 3 ppm CC now you may as well keep your chlorine level elevated until it drops down which hopefully will be in a number of hours.
 
Well I appreciate the help but I just can not get the cc to drop. I have been holding the spa at FC of about 14 but the cc remains at 3. We are not using the tub until this is cleared up one way or another.
Is this a common problem? I think I should be seeing improvement in the CC reading. Should I be aerating the tub? I have been just circulating when I needed to add more bleach to mix well. Why would the CC be so stubborn to drop? Thanks for any ideas. jim
 
The best would be exposure to sunlight, but that may not be possible depending on the location of your tub. Aeration can help remove any volatile disinfection by-products so yes you can try that as well. Having the water be hot (95-104ºF) will also help accelerate the oxidation reactions. Note that non-chlorine shock (MPS) will measure as FC or CC depending on the test kit (usually as FC for FAS-DPD and CC for DPD) and if you've been using that then there's an interference remover if you need to distinguish between chlorine and MPS. I assume you don't have an ozonator in the spa, correct?
 
No ozonator. I have uncovered the tub to expose it to as much light as I can but that will be somewhat sheltered from light though. I read on here somewhere that dropping the temp of the tub helped someone get the CC down. So I did drop the thermostat to 80 to see what would happen. I had the water hot until I decided to try dropping the temp. I am seeing a bit of improvement in the CC this morning from 3 to 1.5 so we are finally headed in the right direction. I started aeration and think I will turn the heat back up to see if that helps. The water does not have an odor to it at all and is crystal clear. Thanks for the help.Jim
 
Well I'm glad it's dropping though the temperature change might have been coincidental. Keep us posted. Having no odor probably means the CC is something like chlorourea. If this sort of problem persists in the future and if the bather load is too high for the chlorine to handle, then since you don't have an ozonator this is one situation where enzymes can be helpful. But get the CC down first since it might have been an anomaly.
 
I have been trying to determine just what path to take next. I don't seem to be making great progress with the SLAM method. It seems that I could go on indefinately with SLAM and not reach the desired goal of eliminating the CC's in the spa. I read an article about the practice of super chlorinating to remove CC's (you can find the article at this link: http://aquamagazine.com/content/post/Shock-and-Gnawing-Doubts.aspx ) And find that there is a persistent organic chloramine which does not react to breakpoint super chlorination. Not being a chemist myself I am led by the article to think that I should dump the water and start fresh. And possibly add an ozinator to the spa. Sounds like the persistent organic chloramines when super chlorinated can produce some nasty gases that are not healthy. Although the Chlorine/CYA shock chart dont seem to be advocating that the shock level be as high as this super chlorination level. My shock level is at FC of 15 whereas this super chlorination level seems to be much higher than that( some 10 times the CC measurement which would have me shocking at FC of 30). They see to indicate that this high level of chlorine above what is required to oxidize the inorganic chloramines is where the harmful outclassing can occur. They do mention using a non chlorine shock perhaps as an alternative as well as dumping the water and starting fresh. My question is which should I do next and should I add the ozonator to avoid this in the future? The water in the spa is about 3 months old if that matters. Thanks for any advice here. Jim
 
There is no magic number and the 10x rule is wrong anyway. Somebody in the past forgot that there is a factor of 5 unit difference between ammonia in ppm N units and chlorine and chloramine (including monochloramine) in ppm Cl2 units and they also forgot that CC will already have chlorine attached to it. The 10x rule came from chlorine oxidation of ammonia, not chlorine oxidation of CC. I'd ignore much of what you read unless it's from a scientific peer-reviewed paper in a respected journal. Higher chlorine levels will oxidize chemicals faster, period. If you want to superchlorinate to any very high level you want, that's up to you. You could do a test with a bucket of spa water if you want to use less chemicals just to see IF this CC will go away with chlorine at all and if so at what level and how long it would take.

It is true that there can be persistent organic chloramines that are slow to oxidize from chlorine, but in a hot spa with residential bather load this is very unusual. There are definitely chloramines that show up after bather load, but usually within 24 hours, again at HOT spa temperatures, they are gone down to <= 0.5 ppm. Yes, you can just replace the water, but it would be good to know what caused this in the first place. Otherwise, you'll just have it happen again and not know why -- perhaps some sort of chemical on the skin (lotion, etc.).

An ozonator may help, but ozone doesn't oxidize everything so it depends on the specific organic chemical that is causing the problem. Odds are it will help, but there's no guarantee. Enzymes might help as well, but again, no guarantee.
 

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I really appreciate the input here. You know much more than I do about these issues in my water as I am quite the armature when it comes to matters of water chemistry and that is why I have embraced the BBB method for its simplicity. I can handle that but these CC that will not dissipate are a mystery to me. This seems to be a situation that the BBB method does not by itself deal with. I don't see how I can determine just what is causing this elevated CC condition and therefore know how to avoid it in the future. Perhaps a test of some pool water in a bucket at high levels of FC would get rid of it and tell me that it is possible but I still would not know what caused the problem.

here is a statement from the aforementioned article:

SeaKlear's Terry Arko notes the problems inherent with superchlorination and recommends the use of potassium monopersulfate (MPS) shock, which he says achieves the same result as breakpoint chlorination. But either approach, he notes, only reduces the inorganic form.
"Organic chloramines," he says, "are only reduced by draining and dilution. One practical way to know if you have a majority of organic-bound chloramines is to test and follow the procedure for determining breakpoint chlorination. If superchlorination or chlorine-free shocking does not reduce the level of chloramines, that would be an indication that there are organically bound chloramines present."

If there is any truth to this statement then I must assume that my only coarse of action here is to drain the water? What would you do if this were your spa? Thanks
 
The CC issue has nothing to do with BBB. Dichlor-only users would face the same problem. You are the FIRST report of high CC in a spa and there's another couple of forums with more spa activity and this problem you have simply isn't seen. Now many spas have ozonators so that is part of it, but there are others without and yet they don't show high CC. So something is special about your situation -- we just haven't figured out yet what that is.

As for SeaKlear's Terry Arko statement, it's only half-right. There are absolutely, positively, organic chloramines that can get oxidized by chlorine. And there are others that form fairly quickly such as chlorocreatinine that may take longer to oxidize. However, since most residential spas don't see this problem, I don't think it's generally an issue.

If this were my spa I'd do a bucket test using spa water and see if superchlorination does anything to reduce the CC. If it does, then I'd do that in the spa. If not, I'd change the water. If the problem shows up again after a water change, then I'd try enzymes to help oxidize more bather waste. If I had never used a biofilm remover at least once since I owned the spa, then I'd use Ahh-Some.
 
In light of what you have said I would like to add that I have used a biofilm remover when I put the spa back in operation after a prolonged time of inoperable condition being stored in an outside environment while being covered but that cover being compromised somewhat. I bring this up simply because I want you to be aware of the path that brought us to this point since that may or may not afford you some insight to the problem we face. I used a product to remove the biofilm from the piping called SeaKlear Spa System Flush. I actually filled the tub twice and drained it to make sure that I did a good job of cleaning the tub before putting it in service. Here's the rub though. I find out some time later that the second pump is not working when this decontamination took place. Therefore some of the piping did not see the proper flow of cleaner through them and maybe did not get thoroughly decontaminated. There was flow but it was intermittent and of little force as the pump was wired wrong causing it to overheat and quit operating almost as soon as it came on. I think this condition did not contribute to the effective use of the system flush. I did not think of this current scenario I find myself in as a result to be guarding against when I discovered this pump malfunction condition. Yet here we are! I don't know if the germ of whatever this spa has going on in it is a result of that lack of full decontamination but I feel that I do need to drain the water and do another decontamination procedure. I have reordered some of the same chemicals I used the first time( Sea Klear Spa System Flush, Power Soak Filter Cleaner). I also ordered new filters but the ones previously used were new when I put the spa in use.

Knowing what you now know and that we were keeping the free chlorine levels at probably higher than required levels at all times and checked the pH also regularly, what do you speculate may be our mistake? If I do the bucket test just how do I go about that? My FC is now 12 say and how much of a sample would be adequate? If say 2 gallons then how much bleach would you add to it to bring it to what FC level? Also is the SeaKlear Spa System Flush an adequate product to use? I simply don't know.
 
We used to recommend Spa System Flush and it was certainly better than Swirl Away but then we found out about Ahh-Some and people comparing them found that Ahh-Some was the best (they also have lab reports comparing themselves to others that show the same thing). So if you have a choice, I'd go with Ahh-Some just to be safe.

1/4 teaspoon of 8.25% bleach in 2 gallons of spa water would be 14 ppm FC.
 
OK Thanks for the information. I did do a bucket test of 2 gallons with a teaspoon of bleach which was overkill and that would have put FC at around 54. checked it and the cc was still at 3. Don't know what I have but it isn't easily affected by FC levels. Already have the Spa System Flush coming. Plan to decontaminate when it arrives and replace filters and drain and refill. Will balance and watch very carefully!!! Thinking of enzymes also. As an advanced strike approach. Or should I wait a bit to see what happens after I get spa back up and running? What would you recommend? Also thinking of adding ozonator. What is your opinion on that. Is it overkill or recommended? Thanks Jim
 
You need to wait hours to see if the higher FC will do anything to the CC. Check it again tomorrow morning. Another thing to try, even though you may not be able to do it for your spa, is to take the bucket outside and expose it to the UV in sunlight, but I'd add some CYA to the water first (a tiny amount to get to 30 ppm or so -- if you have Dichlor you can just add that even though it will increase the FC more).

Since you've got this "bad" water, you can either change it and hope for the best (i.e. that the problem doesn't return) or you can keep experimenting with it until you find a solution. So if you got enzymes you'd add a tiny amount and see if it helps. Again, up to you.

This is truly the strangest thing I've ever seen. A truly "stuck" CC. Something that does not react with DPD directly but does oxidize iodide to iodine since that what the CC test does.

I wish I could give you a definitive recommendation, but I really can't since this is so unusual. Though I would assume that ozone would take care of it, I really don't know since we don't know what this is.
 
I am not smart enough to figure out what this is. I think that I am pointed at just changing the water after decontamination and praying that I get whatever it is in the process. If there is an enzyme that you would recommend after I get started back up with new water I would be interested to know what that is if I end up needing it. You have been most helpful thus far and I just wish I were as informed as you are about these things. Thanks and I will post back if anything changes. Will let you know how it resolves. Thanks Jim
 
Well thanks for the compliment, but I feel like an idiot being completely stumped by this one. So let me give you the full run-down of the types of additional products that can be used, but again since we don't know what this is it's really hard to know which would be appropriate.

The no-brainer product is Ahh-Some since that is known to be effective against biofilms and removes grease and other chemicals some of which result in additional chlorine demand.

After that, it's harder to know what to do but for enzymes I'd recommend something like WatersChoice Spa Water Treatment, Orenda CV-600, or Natural Chemistry® Spa Perfect.

It's also possible to try any non-chlorine shock (MPS) product, but unfortunately that ends up actually showing up as CC in some tests (the DPD test, though with FAS-DPD it usually shows up as FC if there is any real FC in the water -- that is, it doesn't color the indicator dye but it does use up the FAS drops when counting FC).
 
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