Shock the spa right after a fresh fill?

[rubicon]

I understand the need to shock a spa when the water becomes cloudy or another adverse condition exists but I don't understand why you must shock the spa right after a fresh fill. If I am able to start with 4-5ppm Bromine after balancing and building up a Bromide reserve, why is it necessary to shock up to 20ppm? If I do that, how long would it take for the levels to come down to the 4-5ppm I want to keep the spa at? At what level of Bromine would you not want to enter the spa?

In a Bromine tub, how long do you need to run the filter cycle every 24-hours?

 

[Kiss4aFrog]

Re: How do I use Bromine in my spa (or pool)?

Welcome to the forum Rubicon

Is it an indoor spa, outdoor, attached to a pool ....
Please add your pools info to your signature as outlined here: http://www.troublefreepool.com/content/165-getting-started

It's a safety thing. If it's treated city water you might be safe not shocking it but why not just shock it and be sure ?? It's also to kill anything hiding in the spas piping, filter ...
If you shock it usually doesn't take more than a day or two to be safe.
Usually the run time is determined by how much it takes to keep the temp up. I run mine twice a day but the time will vary as I have an unheated basement and it needs more time in the winter then the summer.

 

[chem geek]

Bromine is not as effective an oxidizer as chlorine so to keep the tub clear it usually requires shocking with chlorine on occasion. Doing this at the start after a fresh fill just helps to clean up the water at the start.

None of this is usually necessary when using the Dichlor-then-bleach method. It's bromine that needs some extra help.

If you want to lower a chlorine or bromine level more quickly, you can always add hydrogen peroxide where 3% hydrogen peroxide can be added in an equivalent volume as 6% bleach to counteract that amount of FC (or total bromine if you divide total bromine by 2.25 to get equivalent FC).

 

[rubicon]

Thanks for the info. A quick follow-up -

* How long should the filter cycle run? I am coming off of using Nature2 where I ran it 3x a day for 2 hrs each run.

This tub gets weekend use only which is why I am looking for a sanitizer that can last between uses (sometimes 2 weeks).

 

[chem geek]

Understood.

As for the filter cycle, that depends if you have an ozonator. With an ozonator, it will make more bromine from the bromide bank so you'd need to adjust your filter cycle so that the bromine level was reasonably maintained with the ozone, unless you wanted to supplement with bromine tabs.

With no ozonator, then the filter cycle is just to keep the water clear from new debris and bather waste (the bit stuff like larger flakes of skin cells or swimsuit material). You could probably turn down the filter cycle to be pretty low -- just keep lowering it until you start to see a water clarity reduction and then increase it above that limit so that the water stays clear.

 

[rubicon]

Great suggestion on looking to achieve water clarity with the minimum filter time.

Regarding your earlier suggestion of quickly reducing bromine levels with hydrogen peroxide (if desired), wouldn't that practice minimize the effectiveness of the shock treatment?

 

[chem geek]

I meant if it took a long time for the shock level to drop and you were impatient. The shock shouldn't be needed for more than 24 hours. If you can wait for the levels to get lower, then that's fine. With bromine, you probably don't want to get into the spa if it's at 10 ppm or higher (that's similar to 4.4 ppm FC with no CYA, except bromine isn't as strong an oxidizer).