Shocking my tub

JenF75

Well-known member
Jul 12, 2017
166
Stouffville, ON, Canada
So, I neglected my hot tub for a few days (ok maybe closer to a week), I was only using the test strips and adding chlorine just before using. Now today, I decide to test properly and my FC was at 0 and CC was 7!! Ooops.

At 1050
FC 0
CC 7
pH 8.0
CYA 40
12 oz of bleach added (to achieve shock target of FC 15)

At 1130
FC 1
CC 5
pH 8.0
11 oz of bleach added, 2 oz of pH down added

Can I just continue testing and dosing q30-60 min until I get the CC back down to acceptable levels? Is this safe to do in a spa? We're supposed to be hot tubbing tonight but now I'm not sure it'll be ready or safe to use!
 

jseyfert3

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Yes, testing every 30-60 minutes and adding to maintain a FC of 16 for your CYA of 40 is perfectly fine and safe to do.

Is the water cloudy too?
 

jseyfert3

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Yes, it's cloudy. Lesson learned for me!!
Well, I did this a few months back too, so you're not alone! Forgot to check for a few days after a night of really heavy use and the water went cloudy. You are unfortunately not going to get this cleared up for use tonight. For me, it took a couple days to clear up the cloudy water and after that it smelled of CC so bad that after a few more days of SLAMing I dumped the water anyway.

I would similarly recommend you dump and refill too and don't bother trying to SLAM. It's honestly much easier to re-balance a new fill then to try to SLAM a cloudy tub. If you have Ahh-Some on hand it's always good to run a purge before dumping.
 
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jseyfert3

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Oh, and in the future I also recommend something like the Saltron SWCG. It certainly would have helped my above situation if I had been using it (not entirely, but I may have saved the water)...but ironically I had just done a fresh fill days before the night of heavy use and had balanced the water but not added salt yet, so I didn't have the SWCG running as I normally would have.

The SWCG isn't a complete failsafe, still need to test and sometimes manually add. I usually always do a manual dose of chlorine after getting out after a night of heavy use, and sometimes need to dose the next day too, but it keeps the FC levels up in between uses, which is the best reason to get one.
 
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JenF75

Well-known member
Jul 12, 2017
166
Stouffville, ON, Canada
Thanks for your insight. Hot tub party is cancelled tonight 🤪 LOL. I may need to dump I guess, but I’ll try this for a few days first as my Ahh-some is on order and won’t be here for a few more days anyway.
 
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mknauss

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That level CC test result implies use of MPS (non chlorine shock). Rarely do you see above a 2 or 3 CC from just spent chlorine.
 

mknauss

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No - I am implying that MPS has been used as it shows as high CC - via a test interference.

MPS is Monosodium Per Sulfate. Non chlorine shock. If you have not used it, great.
 

JenF75

Well-known member
Jul 12, 2017
166
Stouffville, ON, Canada
No - I am implying that MPS has been used as it shows as high CC - via a test interference.

MPS is Monosodium Per Sulfate. Non chlorine shock. If you have not used it, great.
Ah, I see. The last time I added Dichlor to my hot tub was Feb 27th, at which point my calculated CYA was 28, so I switched to bleach and have been using that since.
 

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JenF75

Well-known member
Jul 12, 2017
166
Stouffville, ON, Canada
So, this morning my water looks soooo much better! I would say is pretty clear. But my CC is still 3.5, so I'm continuing to SLAM. I've been testing and adding chlorine every hr (not through the night however) and the CC has stayed at 3.5 and not come down since yesterday afternoon. Is there anything else I can do/add to help get that down? I'm still hoping to not empty and refill my tub until at least next weekend, because I'm waiting on my Ahh-some to arrive (it's being detained at the border for some reason :rolleyes: )
 

JenF75

Well-known member
Jul 12, 2017
166
Stouffville, ON, Canada
Ughhh, what is going on?! I've been SLAM'ing my hot tub since yesterday and I cannot for the life of me get my CC down at all. My numbers today:
Time. FC. CC pH. Action
at 0755
1​
3.5​
7.7​
11 oz of bleach added
at 0945
6.5​
3​
10 oz of bleach added (now aiming for FC of 20)
at 1245
5.5​
3​
11 oz of bleach added
at 1625
5.5​
3 21 oz of bleach added, now trying 10x the CC level as suggested in an article
at 2015
13.5​
3.5​

My CC has been right around 3 since 1pm yesterday and hasn't moved. What am I doing wrong?! I've had to ease up on testing a bit because I'm running low on reagents and need to make it last until my new order arrives (it's difficult to get in Canada right now).
 
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jseyfert3

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My CC has been right around 3 since 1pm yesterday and hasn't moved. What am I doing wrong?! I've had to ease up on testing a bit because I'm running low on reagents and need to make it last until my new order arrives (it's difficult to get in Canada right now).
I doubt you're doing anything wrong. You have a massive FC demand right now. As FC breaks down waste CC's are always generated. So I'm not terribly shocked you have a high CC right now.

As a point of comparison here's a timeline of what happened to me:
  • Nov 7th: New fill, balanced water.
  • Nov 8th: Finished balancing water. Night of heavy use. Forgot to add chlorine after we got out (was a tad drunk...) and SWCG was not operating. Then I made the stupendous call to ignore it and not check it for a few days...
  • Nov 11th, 9:46 AM: Did not even measure FC/CC, I assumed both would be zero. Added 11 oz of 7.5% bleach.
    full
  • Nov 11th, 2:12 PM. FC at 0.5. Added another 11 oz of bleach.
  • Nov 11th, 7:42 PM. FC 3, CC 1.5. Added 9 oz bleach.
  • Nov 11th, 9:20 PM. FC 9, CC 2.0. Added 4.8 oz bleach.
  • Nov 12th, 7:35 AM. FC 3.5, CC 1.5. Added unlogged quantity of bleach.
  • Nov 12th, 8:47 AM. FC 11, CC 1.5. Added 3.4 oz bleach.
  • Nov 12th, 12:50 PM. FC 8.5. Add 5.2 oz of bleach.
  • Nov 12th, 6:50 PM. FC 7.0, CC 1.5. Added 6.2 oz bleach.
  • Nov 12th, 9:39 PM. FC 11.0, CC 1.5. Added 3.4 oz bleach.
  • Nov 13th, 7:57 AM. FC 4.5, CC 2.0. Added 6.5 oz bleach.
  • Nov 13th, 8:13 PM. FC 6.0, CC 1.5. Added 6.2 oz bleach.
  • Nov 13th, 9:18 PM. FC 14.0, CC 1.5. Added 1.2 oz bleach.
  • Nov 14th, 7:38 AM. FC 8.5, CC 1.5. Added 4.7 oz bleach.
  • Nov 14th, 2:39 PM. FC 10.5, CC 1.0. Added 3.4 oz bleach.
  • Nov 14th, 7:32 PM. FC 12.5, CC 1.0. Added 2.2 oz bleach.
  • Nov 14th, 9:28 PM. FC 13.5, CC 1.0. Added 1.6 oz bleach.
  • Nov 15th, 8:52 AM. FC 9.0, CC 1.5. Added 4.4 oz bleach.
  • Nov 15th, 9:25 PM. FC 10.5, CC 1.0. Added 3.4 oz bleach.
  • Nov 16th, 6:26 AM. FC 11.0, CC 1.0. Added 3.1 oz bleach.
  • Nov 16th, 6:17 PM. FC 10.0, CC 1.5. Added 3.7 oz bleach.
  • Nov 16th, 9:41 PM. FC 14.0, CC 1.0. Added 1.2 oz bleach.
  • Nov 17th, 6:43 AM. FC 12.5, CC 1.0. Added 2.2 oz bleach.
  • Nov 17th, 9:27 PM. FC 10.5, CC 1.0. Added 3.4 oz bleach.
  • Nov 18th, 6:41 AM. FC 11.0, CC 1.0. Added 3.1 oz bleach.
  • Nov 18th, 9:36 PM. FC 11.0, CC 1.0. Added 3.1 oz bleach.
At this point a few days later we did use it, and used it a few more times, until on Dec 30th I have a note that reads:
Draining hot tub, refill and balance tonight and tomorrow. CC small was the worst it's been yet

If I recall, even though I got the CC down to 1 where I normally consider it "okay to use" the smell was always worse after the SLAM than it had ever been previously at the same CC level. And unlike previously where. So that, combined with the work and reagents used to do a SLAM, led me to the conclusion that should I ever let something like this happen again I would immediately dump and refill, and not bother trying to do a SLAM.

This was the basis for my recommendation to avoid SLAMing and do a dump and refill. Your extremely high FC demand that backs up my recommendation to dump and refill.

One last note: Is your CC reagent clear or has it gone yellowish?
 

JenF75

Well-known member
Jul 12, 2017
166
Stouffville, ON, Canada
I doubt you're doing anything wrong. You have a massive FC demand right now. As FC breaks down waste CC's are always generated. So I'm not terribly shocked you have a high CC right now.

As a point of comparison here's a timeline of what happened to me:
  • Nov 7th: New fill, balanced water.
  • Nov 8th: Finished balancing water. Night of heavy use. Forgot to add chlorine after we got out (was a tad drunk...) and SWCG was not operating. Then I made the stupendous call to ignore it and not check it for a few days...
  • Nov 11th, 9:46 AM: Did not even measure FC/CC, I assumed both would be zero. Added 11 oz of 7.5% bleach.
    full
  • Nov 11th, 2:12 PM. FC at 0.5. Added another 11 oz of bleach.
  • Nov 11th, 7:42 PM. FC 3, CC 1.5. Added 9 oz bleach.
  • Nov 11th, 9:20 PM. FC 9, CC 2.0. Added 4.8 oz bleach.
  • Nov 12th, 7:35 AM. FC 3.5, CC 1.5. Added unlogged quantity of bleach.
  • Nov 12th, 8:47 AM. FC 11, CC 1.5. Added 3.4 oz bleach.
  • Nov 12th, 12:50 PM. FC 8.5. Add 5.2 oz of bleach.
  • Nov 12th, 6:50 PM. FC 7.0, CC 1.5. Added 6.2 oz bleach.
  • Nov 12th, 9:39 PM. FC 11.0, CC 1.5. Added 3.4 oz bleach.
  • Nov 13th, 7:57 AM. FC 4.5, CC 2.0. Added 6.5 oz bleach.
  • Nov 13th, 8:13 PM. FC 6.0, CC 1.5. Added 6.2 oz bleach.
  • Nov 13th, 9:18 PM. FC 14.0, CC 1.5. Added 1.2 oz bleach.
  • Nov 14th, 7:38 AM. FC 8.5, CC 1.5. Added 4.7 oz bleach.
  • Nov 14th, 2:39 PM. FC 10.5, CC 1.0. Added 3.4 oz bleach.
  • Nov 14th, 7:32 PM. FC 12.5, CC 1.0. Added 2.2 oz bleach.
  • Nov 14th, 9:28 PM. FC 13.5, CC 1.0. Added 1.6 oz bleach.
  • Nov 15th, 8:52 AM. FC 9.0, CC 1.5. Added 4.4 oz bleach.
  • Nov 15th, 9:25 PM. FC 10.5, CC 1.0. Added 3.4 oz bleach.
  • Nov 16th, 6:26 AM. FC 11.0, CC 1.0. Added 3.1 oz bleach.
  • Nov 16th, 6:17 PM. FC 10.0, CC 1.5. Added 3.7 oz bleach.
  • Nov 16th, 9:41 PM. FC 14.0, CC 1.0. Added 1.2 oz bleach.
  • Nov 17th, 6:43 AM. FC 12.5, CC 1.0. Added 2.2 oz bleach.
  • Nov 17th, 9:27 PM. FC 10.5, CC 1.0. Added 3.4 oz bleach.
  • Nov 18th, 6:41 AM. FC 11.0, CC 1.0. Added 3.1 oz bleach.
  • Nov 18th, 9:36 PM. FC 11.0, CC 1.0. Added 3.1 oz bleach.
At this point a few days later we did use it, and used it a few more times, until on Dec 30th I have a note that reads:


If I recall, even though I got the CC down to 1 where I normally consider it "okay to use" the smell was always worse after the SLAM than it had ever been previously at the same CC level. And unlike previously where. So that, combined with the work and reagents used to do a SLAM, led me to the conclusion that should I ever let something like this happen again I would immediately dump and refill, and not bother trying to do a SLAM.

This was the basis for my recommendation to avoid SLAMing and do a dump and refill. Your extremely high FC demand that backs up my recommendation to dump and refill.

One last note: Is your CC reagent clear or has it gone yellowish?


Thanks for your response, much appreciated. I can certainly say that the SLAM process is not worth it, definitely a dump and start fresh is a better option. The thing is, I don't yet have my Ahh-some and I really wanted to do that purge on the next fill and also, it's really cold where I live, so emptying and refilling poses it's own challenges (like, we can't just pump the water out to anywhere, it has to go to a drain or freezes and causes a hazard). Just today, I received notice that my order (reagents and Ahh-some) have cleared customs and made it to Canada, so fingers crossed for a bit warmer weather this weekend and I'll be emptying and starting fresh with this hot tub. And then I need to make sure I don't mess up like this again!!

I've also been on lookout for the Saltron mini, but again, not so easy to find here in Canada!! I'll keep looking however.
 
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jseyfert3

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Thanks for your response, much appreciated. I can certainly say that the SLAM process is not worth it, definitely a dump and start fresh is a better option. The thing is, I don't yet have my Ahh-some and I really wanted to do that purge on the next fill and also, it's really cold where I live, so emptying and refilling poses it's own challenges (like, we can't just pump the water out to anywhere, it has to go to a drain or freezes and causes a hazard). Just today, I received notice that my order (reagents and Ahh-some) have cleared customs and made it to Canada, so fingers crossed for a bit warmer weather this weekend and I'll be emptying and starting fresh with this hot tub. And then I need to make sure I don't mess up like this again!!
Perhaps stop trying to SLAM and just dump like 2 cups of bleach in the tub in the morning and two at night and call it good till you can purge and dump this weekend? I don't usually recommend people not test but this is one case were an exception seems to make sense.

I've also been on lookout for the Saltron mini, but again, not so easy to find here in Canada!! I'll keep looking however.
There's other options, such as the ControlOMatic ChlorMaker. I checked Amazon.ca and saw it for CDN$ 479.00 but at USD$382 that's a steep increase over the US price of $276 which is already higher than the price of $230 for the Saltron Mini from SpaDepot.com (where I bought it).

Actually speaking of SpaDepot.com, can you buy the Saltron from them? They say they ship to Canada for $25 flat rate shipping on orders over $100.
 

JenF75

Well-known member
Jul 12, 2017
166
Stouffville, ON, Canada
erhaps stop trying to SLAM and just dump like 2 cups of bleach in the tub in the morning and two at night and call it good till you can purge and dump this weekend? I don't usually recommend people not test but this is one case were an exception seems to make sense.
That's a good idea, I'm done with this SLAMing process. The water looks great anyhow, I'm going to focus on that until I can drain it. And I'll definitely have to check out SpaDepot and see about getting unit from them if they ship to Canada.
 
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