Shock questions

[sjde]

I have a bromine spa. Why is it necessary to use both chlorine shock (Dichlor) and non-chlorine shock (MPS)? Or isn't it?

I usually add a little of both. From what I understand , MPS is a better oxidiser but it is not a sanitizer-won't kill bacteria. However, it does reactivate the bromide to the sanitizing form bromine.

So maybe my question is, other than using chlorine for cost reasons, is there another reason to use it if I am using MPS? Does it help more with clearing up cloudiness or anything else?

I've been having trouble with the bromine reading going too high, so I may stop using it. I'd usually add 1 tsp dichlor and 1 Tbsp MPS to a 375 gallon spa. Sometimes that seemed fine but this time, I started with a bromine reading of 0.5 ppm, adding those brought it to 6ppm (which is fine, though with our ozonator it really only needs to be 1-2). However the next morning (the spa hadn't been used) I checked and the reading was 14! Using a Taylor drop kit.

[bud16415]

Your results with bromine sounded a lot like mine when I was using it for the first year we had our tub. I think the MPS releases the bromine that is attached to what it has killed in the water back into the bromine bank and it doesn’t work instantly so overnight that happened and your dichlor was also converted to bromine thus the spike the next morning. When I was using bromine I also had a similar roller coaster ride with my levels. Adding that small amount of dichlor I wouldn’t call shocking normally a chlorine shock is using a much higher dose.

I use the liquid bleach/dichlor method now and for me it is much simpler and lets me soak when the chlorine level is very low and then I add ether dichlor or liquid bleach (Clorox) after getting out. I start off with fresh water using dichlor and use it daily until the stabilizer hits 30-50PPM then I switch to bleach. The amount varies but for my 350 gallon tub a starting point is 1 TBS per day with normal usage or 1/3 cup of bleach. If the tub isn’t used I will skip a day or add about half that. If we have company or heavy usage with swimsuits that may not be rinsed that good etc. I will add extra when we get out and test the next morning and maybe add more. It is a simple method but requires paying attention.