New Hot Tub - More to Learn

Ok. Clueless here. Just checked the hot tub. FC back down to 0.5. My CC is better, at 6. But why did FC drop THAT much? I am doing the chlorination process from the pool school, and yesterday I got my FC to 11.5 (CC yesterday was 16). We went in for about 30 min and I didn’t add anything because I thought it was still at shock levels, but then today, this. My only guess is that maybe the FC was used up to try to kill the CC since that dropped pretty well. But I am nowhere near an expert on this, so not sure what to do. I added another 10 ppm of Dichlor, which will be my last dose of that before switching to bleach because my CYA is nearing the 20ish level now prior to adding this last dose of dichlor.
 
So I dug into Frog System's website a bit. The SDS for the Frog Ball lists the contents as:
  • 1,3-dichloro-5,5-dimethylhydantoin (81%)
  • 1,3-dichloro-5-ethyl-5-methylhydantoin (16%)

This is not dichlor as "dichlor" typically used in spas is 1,3-dichloro-1,3,5-triazinane-2,4,6-trione in the same naming scheme. Don't worry about understanding that, because I certainly don't! I'm just listing it to show it's different. And it's certainly not trichlor either.

So, curiously enough, they also list the following on their website:
NOTE: Why @ease Test Strips? The SmartChlor cartridge forms a chlorine reserve that will be inaccurately measured as total chlorine on other test strips. Unlike conventional chlorine, the SmartChlor reserve readily shifts to free chlorine as needed, maintaining spa health with a low level of chlorine.

So, without understanding the chemistry, I'm putting 2+2 together and saying your crazy high CC reading is because the Frog ball added those CC's, to create a "buffer" of chlorine (or to try anyway). Perhaps you can get rid of them by keeping a high level of FC for a bit, perhaps they will be difficult to get rid of. If they don't drop, a drain and refill would be in order.

Next fill, no funny stuff and your spa should be as easy to take care of as your pool. :splash:
 
So I dug into Frog System's website a bit. The SDS for the Frog Ball lists the contents as:
  • 1,3-dichloro-5,5-dimethylhydantoin (81%)
  • 1,3-dichloro-5-ethyl-5-methylhydantoin (16%)

This is not dichlor as "dichlor" typically used in spas is 1,3-dichloro-1,3,5-triazinane-2,4,6-trione in the same naming scheme. Don't worry about understanding that, because I certainly don't! I'm just listing it to show it's different. And it's certainly not trichlor either.

So, curiously enough, they also list the following on their website:


So, without understanding the chemistry, I'm putting 2+2 together and saying your crazy high CC reading is because the Frog ball added those CC's, to create a "buffer" of chlorine (or to try anyway). Perhaps you can get rid of them by keeping a high level of FC for a bit, perhaps they will be difficult to get rid of. If they don't drop, a drain and refill would be in order.

Next fill, no funny stuff and your spa should be as easy to take care of as your pool. :splash:

Wow, thank you so much for putting all this time into researching my little spa! I certainly never expected that. It's what makes TFP so awesome! I looked at the @Ease ball page as well and not having understood any of the jumbled mess, I only picked up the fact that it said the ball would keep my spa with nice low FC levels between 0.5 and 1. I may not know much, but I KNOW that is way too low! I pulled out the ball on 3/21, but unfortunately, it had already done 5 days of damage by the time I pulled it. So it very well could be that it messed up my chlorine levels. So this morning, I am going to Walmart to get a good batch of chlorine and sit down and figure out how to get this pool "SLAM"med.

Thank you!!
 
I have been doing the slam procedure with the hot tub since 1 pm yesterday and my FC is at 10 and my CC is still at 5.5, so I am going to continue through tonight and probably tomorrow too. My question is can we increase the slam level to 15 instead of keeping it at 10? I still don’t have a strong understanding of the chemicals, so what does having it at 10 do that 15 or 20 won’t do faster? Would there be damage to the tub or filters or something else?
 
Ok, so here is a wild thought, and I am just guessing here. But that frog ball was supposed to build up a chlorine reserve which would measure to show a high total chlorine (fc+cc). So maybe what you need to do is not add anymore chlorine so that the bound chlorine that is showing up as cc will get used. My thinking is that the bound chlorine (that is showing up as cc) isn't getting used since you are keeping the fc level high.

Other 2 options would be to drain and start over or see if you can get one of the folks that really understand chemistry to look at this thread and see if they can figure out the chemistry.
 
Ok, so here is a wild thought, and I am just guessing here. But that frog ball was supposed to build up a chlorine reserve which would measure to show a high total chlorine (fc+cc). So maybe what you need to do is not add anymore chlorine so that the bound chlorine that is showing up as cc will get used. My thinking is that the bound chlorine (that is showing up as cc) isn't getting used since you are keeping the fc level high.

Other 2 options would be to drain and start over or see if you can get one of the folks that really understand chemistry to look at this thread and see if they can figure out the chemistry.

Thats a good theory. We may kick it up to a slam level of 12-13 today, as my cya is 20-30. We were going on the conservative side, but we may need to go to 12. The reason I am going to try this today is because when I first started adding chlorine, my FC increased, but so did my CC. Now after 24 hrs of the slam, my FC is up but my CC is cut in half. So maybe I just need to boost the FC up higher to get rid of the rest of the CC in there. If that doesn’t work, then i’m Going with your theory. ;)
 

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This morning's numbers are:

FC: 10.5
CC: 1
pH: 7.6
TA:70
CH: 120
CYA: 40

Looking better. My TA seems to be creeping up though. Is this an ok number to live with, or should I add baking soda? Pool math didn't respond when I put in the numbers. I still want my CC to drop a bit more too.

Thanks!
 
My spa always has .5 - 1 cc. So to me that is normal. Dont add baking soda, you really want your ta to be lower, somewhere around 50 - 70 to stabilize your ph.

I should clarify, baking soda would make your ta and to some extent ph go up. You want to add acid to lower ta and ph. Each time you add acid, your ta will go down some. If you want to lower ta aggressively, lower ph to 7.2, then aerrate to raise the ph to 7.8, then keep doing that until you get your ta to where you want it.
 
This morning's numbers are:

FC: 10.5
CC: 1
pH: 7.6
TA:70
CH: 120
CYA: 40

Looking better. My TA seems to be creeping up though. Is this an ok number to live with, or should I add baking soda? Pool math didn't respond when I put in the numbers. I still want my CC to drop a bit more too.

Thanks!
Most spa users need a TA around 50, but this isn't an exact number. If your pH is stable at 7.6, then that's fine. If you find your pH climbing, then you'll need to drop your TA.

Definitely don't add baking soda, as that will raise your TA and pH.
 
My spa always has .5 - 1 cc. So to me that is normal. Dont add baking soda, you really want your ta to be lower, somewhere around 50 - 70 to stabilize your ph.

I should clarify, baking soda would make your ta and to some extent ph go up. You want to add acid to lower ta and ph. Each time you add acid, your ta will go down some. If you want to lower ta aggressively, lower ph to 7.2, then aerrate to raise the ph to 7.8, then keep doing that until you get your ta to where you want it.

Most spa users need a TA around 50, but this isn't an exact number. If your pH is stable at 7.6, then that's fine. If you find your pH climbing, then you'll need to drop your TA.

Definitely don't add baking soda, as that will raise your TA and pH.

Thank you both! Not sure what I was thinking on the baking soda. Maybe I was reading it wrong. I’ll go ahead and test the water for pH and FC/CC later this evening when my chlorine will probably drop some, and my pH will be a bit more reliable. I’ll leave the TA alone and see how things go.
 
Got the CC under control. It's consistently 0.5 - 1. The problem now is that my FC dives down to 1.5 by morning. What's up with that? We are in it for no longer than 30-40 min, and I always put in about 3 ounces of bleach after use. I guess it's still trying to balance itself out?
 
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