Type of shock to use with bromine sanitizer

[ch3cooh]

Hi all,

I have recently inherited a hot tub with a new house. I had it checked by a local pool company everything checked out well (all heaters/pumps work, jets work, etc.). Its capacity is 1330 litres and it is above-ground.

The previous owners were using bromine tablets in a floater as a sanitizer, which I plan to continue using. However, the shock they used was calcium hypochlorite. I am now exploring 3 options for a chlorine-based shock:

1) Continue with calcium hypo. The water supply in my area is considered hard, so I am not sure how quickly calcium hardness levels would build to the point that I would need to drain earlier if I use this method.
2) Use dichlor. I would prefer to avoid this if possible, since I do not want to deal with buildup of CYA and the many potential downsides of that, which I have read about on this forum (decreasing effectiveness of chlorine; increased chance of pseudomonas taking hold).
3) Use bleach (sodium hypochlorite). I have not read any specific reports of bleach being used as a shock with bromine tablets as the sanitizer, but I would appreciate input regarding this method.

I realize I left out non-chlorine shocks (like MPS), but I decided I want the algaecide/"killing" benefits that come with a chlorine-based shock. I am still open to all ideas...

What recommendations/insights can you suggest?

Thank you,
Matteo

 

[Krulligo]

I use straight 12% pool chlorine as shock in my tub that I use bromine in. It works perfectly fine. You can use household bleach as long as it doesn't have any additives or scents. You need to make sure you have a good bromine bank especially when you have just changed up the water. I give my tub a small shock every time I finish using it, and a larger shock if I haven't used the tub for a week or two and the bromine is starting to become too low. Has been working perfectly fine for me.

There is a good article stickied in this forum about the use of bromine in hot tub. You should give that a good read which will also explain that regular bleach can be used as a shock.

If your water is already very hard I would stay away from calcium based chlorines. From my understanding, Dichlor should be fine as CYA has no impact on bromine, but why use that when regular chlorine is fast and effective without any additional additives.

 

[ch3cooh]

Thank you for your reply, and thank you for pointing me to the stickied post. It has been very informative.

I am going to go the bleach route for shocking, and I will need to get some sodium bromide as I was not aware that I had to establish a bromide bank on new fills.

 

[Krulligo]

Thank you for your reply, and thank you for pointing me to the stickied post. It has been very informative.

I am going to go the bleach route for shocking, and I will need to get some sodium bromide as I was not aware that I had to establish a bromide bank on new fills.

You don't necessarily have to establish a bromine bank. If you don't, your tub will essentially be a chlorine tub at the start until you have dissolved enough bromine tablets that you have built up the bromine bank with over time. If you are doing this you should monitor your sanitizer more frequently and add more chlorine when necessary. But much easier if you can just establish a bromine bank to begin with.

I see you are in Ontario, Canada. Sodium bromide is quite hard to come by (you can Google Canada's regulations on Sodium Bromide to understand why). Some people rely on crushing up bromine tablets to more quickly establish their bromine banks.

 

[ch3cooh]

Yes, I am in the Cambridge area. I was able to find some Sodium Bromide online and it arrived earlier this week.

The floater with tablets in it has been in the tub for the past 2 weeks and the tub has not been used during this time. I’ve shocked weekly with chlorine.

Although there is likely a sizeable bromide bank present already, I’ve seen it posted here that having extra bromide in your bank doesn’t hurt, so I was planning on adding some sodium bromide anyway to be sure that the bank is sufficient. I haven’t heard that there is an exact way to know this…

 

[Krulligo]

Yes, I am in the Cambridge area. I was able to find some Sodium Bromide online and it arrived earlier this week.

The floater with tablets in it has been in the tub for the past 2 weeks and the tub has not been used during this time. I’ve shocked weekly with chlorine.

Although there is likely a sizeable bromide bank present already, I’ve seen it posted here that having extra bromide in your bank doesn’t hurt, so I was planning on adding some sodium bromide anyway to be sure that the bank is sufficient. I haven’t heard that there is an exact way to know this…

Yea I don't see the harm. It's pretty much like adding salt or sodium chloride. Harmless and concentrations need to be really high to start noticing an effect on your water. Also since you are dissolving bromine tablets it keeps adding to your bank, so your bromine bank is dynamic and keeps growing and growing until you finally swap out your water.

From my understanding, all you are doing when adding chlorine as a shock is interchanging the bromine ion into a chlorine ion, and this intern activates the bromine ion into a sanitizer. If there is not enough bromine ions in your bromine bank, then the unused chlorine will just stay as chlorine until it's used up or degraded.

 

[JoyfulNoise]

If this is a used tub, you should not use the water until you have done a purge with Ahhsome biofilm remover. You will be shocked by all the crud that it loosens up and releases from the plumbing. Well, shocked and nauseated too.

 

[ch3cooh]

Noted. I'll look into getting some. Thank you.

 

[The Mule]

Ch3cooh
In my 130 US gallon hot tub, about 1 tablespoon of crushed up bromine tablets*, the kind used in a floater, seems to be about all that was necessary to establish a bromine reserve.
* 55% 1 bromo 3 dichloro 55 dimethylhydantion (man, that's a big word, lol)

 

[ch3cooh]

Thanks for that @The Mule. I'm sure I have more of a reserve than I need considering I also added some sodium bromide granules...