CC too high??

flybyjohn

Member
Nov 27, 2024
9
Helena, Montana
Hi, I am still a newbie here in the water, maintenance worldand I’m trying to figure out my water chemistry. I am able to keep my TA and PH steady and able to correct it quickly when needed. I have a tailor 1005 test kit. I know not many people use the frog @ ease here however I have nine smartchlor cartridges I would like to use before deciding if I want to switch to another system. So even though I know comments to switch to a different system are probably with good intentions, I would like to just discuss the situation I am in now.

My system and water chemistry tested today are as follows.
2024 Jacuzzi J335 hot tub with 350 gallons of water
Filled from well water two months ago. Have added 50 gallons of softened water in that time due to evaporation.
Montana temperatures in the last two months have been mostly between 10 and 45°F.
Water temperature 102°F
TA 50
PH 7.5
Borates 50 ( from borax with muratic acid )
CH 280 as close as I can measure(I have lots of iron and maybe other metals in the well water)
I am using the frog @ease Jacuzzi system with the cartridges attached to the filter.
I have one mineral stick in inside the filter.
I use MPS as a shock about once every week or two.
My wife and I are usually the only ones using it and we bathe before we get in.
The tub has an ozonator and UV light. I run the circulation pump 24 hours a day.


Water has been clear , as far as I know, I don’t have very much experience with a hot tub. I have never really tested the free chlorine or combined chlorine before using my test kit because the frog ease system I assumed would not be able to be measured accurately.

Here is where the fun began. I purchased some frog chlorine cartridges from eBay and should have known better but they had a round, 7 ounce puck inside the cartridges instead of loose smartchlor. I assumed that maybe frog used a different process for them because the outside of the cartridges looked identical to the official frog cartridges. I put one in the hot tub and the frog test strips showed chlorine was good. Second day I noticed a very strong chlorine smell and checked the cartridge and it was unbearable because the smell was so strong. I called King technologies, the manufacturers of frog and found out that king technologies does not use any round pucks in their smartchlor cartridges. They informed me it was probably a Trichlor tablet. I pulled the cartridge out immediately check the pH and it was down below 6.8. TA was also down to 30. I used baking soda to raise TA to 70 and ph to 7.6. I then replace the cartridge with an official frog smartchlor cartridge and left the cover off the hot tub for the entire day. I think I lost about an inch of water with the outside temperature below freezing.

I tested the free chlorine and combine chlorine with the Taylor 1005 test kit. The free chlorine tested at approximately zero to 0.5 and the combined chlorine was showing off the charts. I diluted the water 50-50 two times and tested again and I got somewhere between 2.5 and 3 for combine chlorine. With the dilutions that should give me approximately 10 to 12 ppm of combine chlorine and still no significant free chlorine. I shocked with 2.3 ounces of MPS twice because of some information I got from YouTube telling me that by shocking the combined chlorine it would turn into free chlorine. I have since discovered by reading this form that that probably does not happen.

I have heard that MPS will show as combine chlorine falsely but don’t know the science behind it. I have also heard the smartchlor could also show as combined chlorine. My question is do I need to worry about the 20 to 24 ppm of combined chlorine that is showing on my test. After accidentally adding the trichlor for approximately 36 hours, I was thinking it might be a good time to run an ahh-some purge and start fresh with new water. The water is currently two months old. I am really hoping the tricolor didn’t do any permanent damage to my tub being in there for about 36 hours. I measured the weight of the tricolor tablet I removed and approximately 1.8 ounces of the 7 ounce tablet had dissolved in the 36 hours.

Is a purge and refill advised in my current situation. The weather is supposed to have a high of 30 degrees Fahrenheit this weekend and I can probably do it then if needed. Water going in will be approximately 43° from the well and takes approximately 30 minutes to fill. I have a pump to pump the water out so a drain and refill should be able to be done without anything freezing up in the tub.
 
Last edited:
That was great information PoolStored. However it even leaves me with more questions. Right now I have a strong smell from the hot tub when I lift the cover. It is not a chlorine smell, but I can’t quite determine what it smells like. That article states that the byproducts are sulfate salts. I’m not quite sure what sulfate salts would smell like but the odor from the tub I would describe as being kind of like a musty cave/dirt smell.

So I am still a little confused about the MPS showing up as combining chlorine on the test. Is this the MPS that did not get completely neutralized in oxidizing or the residue or byproducts after the oxidation occurred. So to say it a different way, could my high combine chlorine test results mean that I have extra unused MPS in the water or that I have put too much MPS in the water and the byproducts have built up overtime to show a high combined chlorine test.
 
Dunno on the smell.

To be clear - MPS shows up as excess FC on the DPD-FAS titration test (R-0870 & R-0871) and it shows up as CCs on the DPD only test (R-0001/R-0002 & R-0003).

It only shows up as CC on the FAS-DPD test IF the FC level is zero.

You should not add MPS and dichlor (smartchlor) at the same time. Doing so only defeats the intended purpose of the MPS which is to oxidize organic waste BEFORE chlorine can react with it. When you spike both the chlorine levels and add an additional oxidizer, the two can work against each other.

Next time add the MPS first and let it work for 24 hours before adding more chlorine.
 
Thanks PoolStored. The Smartchlor is a cartridge and stays in the pool all the time. It kind of slowly releases the chlorine. From the limited actual literature I can get off the internet, with the Frog system you should never add dichlor except for the initial fill and that is just to shock and jump start the sanitation since the cartridge releases it so slowly.
 
  • Like
Reactions: PoolStored
So I guess what I was thinking is that you don’t really add the smartchlor, it is just always in the tub, under the filter cover. The chlorine level never gets spiked with the Frog system. Are you suggesting that every time before I use MPS I should take out the smartchlor cartridge and then put it back in after the MPS does this thing?
 
So I guess what I was thinking is that you don’t really add the smartchlor, it is just always in the tub, under the filter cover. The chlorine level never gets spiked with the Frog system. Are you suggesting that every time before I use MPS I should take out the smartchlor cartridge and then put it back in after the MPS does this thing?
Yes. Let's add @RDspaguy, @JoyfulNoise and @Mdragger88 to see what they say...

I'd purge and refill...
 
Last edited:
Smartchlor cartridges use a type of solid chlorine similar to what is used in toilet tank sanitizing pucks. It registers as CC and very little FC. It’s a known issue with the Frog@ease and SmartChlor systems. You’ll have to just manage total chlorine instead of FC/CC separately.
 

Enjoying this content?

Support TFP with a donation.

Give Support
I have smelled the type of smell before, just not sure where. I want to say a caustic smell. I was thinking that the smell
Came on after shocking it with the mps. I double shocked it thinking I could reduce the combined chlorine. So maybe the smell is unused mps in the water.

I do know exactly everything I put into the water but I don’t know exactly what it might have turned into. I’m sure the dissolved solids are high as I chased the ph and ta up and down for the first two weeks.

I have decided to do my first purge, drain and refill tomorrow if the temp gets up to 30. I know a lot more about balancing the water now and can eliminate a bunch of chasing the ph and ta around now.

I have a lot of iron in my well water. What are the negatives of having that in the tub and is there a way to filter it out if it is not any good for it.
 
ph and ta around now.
High TA and low pH, and aeration cause pH rise.

When your TA is 50-80, your pH will likely be stable between 7.8 and 8.0. If you continue to drive pH down to say 7.2, you will be lowering TA significantly. Manage your pH and keep it in the 7s or 8.0. With a TA of 60-80, it should be fairly stable around 7.8-8.0. When your TA is that low, stop lowering pH below 7.8 or so.

Have you reviewed this?
 
You can try to “save” this smelly water by using liquid chlorine to do the
SLAM Process
but you must know your cya level & have an fas/dpd test to do so safely.
I would stop with the mps - while oxidizing is important it is not a sanitizer. Also the test interference is a complication.
Proper sanitizer levels at all times are imperative or things get funky.
Chlorine is both an oxidizer and sanitizer.
If a few rounds of the slam process don’t cure it then its purge & refill time.
Many people find that the frog dispensers either don’t provide enough fc or too much.
After clearing this issue up, If you wish to continue with it you need to monitor closely and supplement with liquid chlorine as needed. Many find it to be an expensive hassle especially if you are needing to supplement anyway. Easier to just dose the tub manually with much more economical liquid chlorine/dichlor(as needed) and know where you stand.
 
  • Like
Reactions: JoeSelf
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.