Chloramines always present - why?

dimetime

Member
Apr 6, 2020
9
North West
I've got a hot tub, 425 gallons, bullfrog. New filters that are rinsed weekly and degreased with tsp monthly.
I use the bleach method along with a drop in swg and salt.
I use muratic acid to get TA to about 40-50 and pH is stable at 7.6.
I add CYA to about 30.
After using the hot tub, the swg can easily produce FC to about 6-8 the next day.
Sometimes I add extra 6% bleach if more people have used the tub.
I don't normally use MPS but have a little.

Problem is this, always high CC. After doing chlorine shocks or using MPS, it rarely goes below .5. It is often at about 1, sometimes 1.5. If I shock it heavily with bleach, it drops some. I've left the swg in and running 24/7 for a few days, and the FC is the same as if I superchlorinated it. I open the tub up most every day for an hour. I've drained and cleaned with the ahsome product twice and put new filters in, but the CC always seems to rise to about 1ppm.

I'm comfortable with the methods described here. I am confident they tub does not go below a couple FC. I rinse before and after use.

I must be missing something but I don't know what it is. I've read lot's of forum posts and articles about CC. It was not an issue for a long time, but now my skin reacts to it, somewhat dry and itchy. The few times I've let the swg churn away for a few days without using it, the CC drops to near zero (maybe .2-3). When the FC drops to about 6-8 and I use the tub, it's nice. After an hour there is still FC of about 2, so I assume it is not exhausted and the swg starts to rebuild it after I am out.

Any insight would be appreciated.
 

dimetime

Member
Apr 6, 2020
9
North West
I had read that some time ago. It's a good refresher.
The mystery is that I've only used the MPS a few times in the last couple weeks because I cannot understand why I'm suddenly getting some itching. The constant presence of around 1 ppm CC even though I have shocked and SLAMed numerous times is the mystery.

I have even used the Ahsome filter cleaner thinking it was too oily but the problem persists.

I wonder, even though the swg can generate FC up to where it should be, if perhaps it doesn't do it quick enough after a soak, and adding bleach might help. That would of course defeat the purpose of the swg.
 

dimetime

Member
Apr 6, 2020
9
North West
Twice in fact. Very little Gunk came out either time, and I read about possible contaminants getting into the filter, so I replace the filters with brand new ones after the last cleaning. I feel like I've read enough fun places like this do you understand that I'm doing almost everything correctly, I just can't figure out why I'm almost always at 1 ppm CC.

I thought perhaps I may have hot tub rash, but it's definitely not that it's some sort of reaction when the CC is high. If I shocked for multiple days and get it down to between 0 and 5 then I don't have the reaction. I'm going through the dpd test reagents like crazy, getting my FC perfect to where I want it before I get in and it doesn't seem to matter if I'm at 0 or 8, it's when the CC is high did I get itchy.
 

jseyfert3

Bronze Supporter
Oct 20, 2017
682
South-Central WI
How much do you use your tub? Curious as my wife and I have noticed somewhat dry itchy skin at times, but this was during winter so dry skin is already an issue. I just figured our long (1-2 hour) soaks in 100 °F water was drying out our skin (I imagine the chlorine will also help dry out skin, since it does oxidize oils slowly), especially as we were doing these soaks daily wince we had just bought the house with the tub and were excited to use it. I don't think it was a rash because we'd just use skin moisturizer which reduced the itchiness (as it does with non-hot tub induced dry itchy skin) and the next morning it would be gone. I figure a rash would stick around longer, and skin moisturizer wouldn't help with it.

On a related note I too often see a CC of ~1 if we are doing long soaks every day or every other day. Over a period of non-use that slowly drops away. I could be wrong (I am a lot), but I figure it's somewhat normal due to the small volumes and high bather waste.

I don't know how much you use your tub, but could it just be that lots of long soaks, combined with somewhat dry winter air, might simply be drying out your skin and making it itchy, and the CC's are just because the tub is in heavy use, and not what's drying out your skin? Someone please jump in and correct me if this isn't a reasonable possibility.
 

dimetime

Member
Apr 6, 2020
9
North West
Good response. Indeed I do use it nearly every day, between 45min to 2 hours. Mostly it's two of us. I definitely notice when the CYA is low as the chlorine become an irritant. With proper CYA and FC levels, we have become more prone to itch and "bumps". When kids and friends join us, we are itchy but they are never. I can only imagine we are in it so much that as you elude to, our skin is dry or somehow more sensitive the more time we spend soaking.

In the last week I have started adding about 4-8oz of bleach after use. This has made a large difference in the CC. I know MPS can cause improper readings, but I have not used much of it and I also read numerous times that the interference goes away after 24 hours. Regardless what I am seeing now is that my swcg probably cannot make FC fast enough after we use the tub. Adding 4-8ppm of bleach I assume begins sanitizing again as we burned up all the FC while we were in the tub. Makes sense I guess although I thought the way the swcg worked was by "super-chlorinating" a given volume near the cell so that CC's in that given volume would be broken up.

In hindsight it makes more sense that such a long soak by two people would exhaust the 8ppm FC that I try to maintain with the swcg when the soak begins. The last test two days ago showed very nearly no pink at all, easily cleared up by one drop. I should probably do the math on amount of FC generated per hour vs the amount of time required to sanitize etc. Probably would show the swcg cannot do what I thought it would. My fault I guess.
 

dimetime

Member
Apr 6, 2020
9
North West
Maybe someone could straighten me out. I've got to be doing something wrong.
I drained my tub again, and rinsed. Filled and began adding dichlor over a few days until CYA was calculated 30ppm.
During this time I added MA to drive down alkalinity and added borates to 50ppm, using MA until it settled out at 7.5pH. The pH is always stable, it never varies no matter what I do except add MPS or top off with fresh water.

Regardless, even with new filters, I continue to fight CC. I have not put salt in this go around to see what bleach only will do. I have not shocked it with MPS. I have been limiting my use to one hour with two people. I'm shooting for about 5-6 ppm FC when I get in and add about 8 oz of 6% bleach afterward. We rinse off before we get in, every time.

The CC keeps going to about 2ppm. I then shock to about 27ppm FC. Overnight it will drop to 22ppm FC with 1ppm CC. If I really add a lot of bleach, say up to 35ppm FC then eventually I get it down but, even if I don't get in the tub, after it goes down to about 6ppm FC the CC are back up to 1.5-2! This makes no sense to me at all. How can I SLAM it, way above where needed, yet it does not go down? Or it goes down if I "super slam" it but goes back up (the CC's) even though it hasn't been used.

I just don't get it. I ordered the large containers of FAS-DPD reagents so I'm testing 6 times a day.

It cannot be this hard. And this without my SWG even being used. I have twice used Ahh-some with 2 clean water changes since last Ahh-some purge. So I've drained and filled 3 times in last 8 weeks! This is city water and upon initial filling after balancing there are no CC at all.

What am I doing wrong here? Side note, with warmer weather I've left the lid open all day, at 27ppm FC and the CC goes from 2 to 1ppm. I did unhook the ozonator, so this is bleach only.

Any help?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
16,481
Northern NJ
What am I doing wrong here? Side note, with warmer weather I've left the lid open all day, at 27ppm FC and the CC goes from 2 to 1ppm. I did unhook the ozonator, so this is bleach only.

I would not worry about a CC of 1. That just shows normal sanitation. Keeping your spa cover open will tend to burn off the CCs but it will also let in any pollen and otehr stuff in your air that can create CCs.
 

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dimetime

Member
Apr 6, 2020
9
North West
Yeah I thought about the debris it introduced but was trying to, as you say, burn off extra CCs. I cannot understand why I add so much bleach and test it at more than SLAM level, and even after 24 hours the FC is still over SLAM level but the CC refuses to go to 0 unless I add way more like 15-20x FC to CC. I measured my CYA which was between 20 and 30, so have been using the 4-6 ppm FC as my target point. I realize the SLAM may not be 12 as the CYA chart suggest but is really 10x CC, this is quite frustrating as it does not seem to follow the advice everyone gives here. I must be doing something wrong but I'll be darned if I can figure out what it is.
 

dimetime

Member
Apr 6, 2020
9
North West
They do use chlorine but it does not register on the fas-dpd test. I might suspect more except it was about 2 weeks before I had to top it off and I was already struggling with this issue.

I had thought that we were going through about 4 PPM of FC a night because for the first four or five days adding 4 oz of bleach was keeping us at the Target level of free chlorine and 0 chloramines. Then it's like a button was pushed and the chloramines were way higher than it should have been but we didn't do anything different that I know of. and then they won't seem to come back down without what I would consider a very excessive amount of free chlorine present. One thing's for sure, the 10x rule is not applying here.

It's probably user error but I thought I was understanding it all.
 

Rocket J Squirrel

Silver Supporter
Bronze Supporter
Jun 7, 2018
723
Alamo, CA
I'm not sure you answered my question about testing fill water for CC. My fill water also registers 0 FC, but 1.5 CC. They add chloramines on purpose. Plus, it's not constant. I suspect our municipal water additives change periodically, perhaps seasonally, and sometimes so does our actual water source reservoir. So the better question may be have you tested your fill water for CC lately?
 

dimetime

Member
Apr 6, 2020
9
North West
Sorry. I did not elaborate. Yes, no FC or CC in water according to FAS-DPD test. But as stated, over a rough two week period, after new refill and after initial balancing, 0 CC.
 
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