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I like shocking with non chlorinated shock,why double/triple your sanitation levels??I guess it would depend on how much you use. As far as waiting that also would depend on how much dichlor you use. The method I use if the water gets nasty, 1/2 cup of non chlorinated shock,wait 30 min running pump on low speed,then 1/4 to 1/2 cup chlorine depending on tub size, run pump again. Add bright n clear run filter pump off and on through out the day if needed.Check PH/ALK.That should clean up any mess if you should have one.Opinions will vary I am sure.
I'm not sure that SpaNE was asking about the worst case scenario that you describe...One varied opinion...
I also prefer shocking with non chlorine shock. It is fool proof. If you use too much, the residual waits for some thing to oxidize; if you use too little, it oxidizes as much as it can. You do not have to wait to use your spa. It is a more complete oxidizer. The disadvantages are increase in TDS, is more expensive and it does not superchlorinate.If you shock with chlorine, you must add enough to reach breakpoint chlorination. If you do not add enough, then you have not shocked. Shocking with dichlor adds to CYA. It is probably best to wait until your free chlorine level backs down to 5 ppm to use the spa. This generally takes about one day, though you certainly could use the spa with 5-10 ppm chlorine if you don't mind it.
I'm not sure what "superchlorinate" means in terms of a disadvantage to shocking with non-chlorine. I'm also unsure how to interpret breakpoint chlorination.
OK...so I normally add 1/3 oz dichlor to my 335 gal tub after a nightly soak. This generally brings by free chlorine to around 3.If my total chlorine is 5 and my free is 3, my combined must be 2. If the rule of thumb is to raise 7-10 times of combined to reach breakpoint - I would need to add about 2 oz of dichlor to shock. Correct?I'm assuming that if I add 2 oz it will take at least 2 days before chlorine is back down to 3 again. Correct?
I have a 325 gal tub, how much MPS must I add to superchlorinate? I tried using MPS before to shock but I can't get the reading up high enough to superchlorinate. Then I go back to dichlor to do the job that MPS won't do.And how much dichlor would you use after each soak to keep the 3-5PPM reading?Thanks to all.