spa oxidizing shock


Silver Supporter
LifeTime Supporter
Jun 22, 2014
Houston, Texas
Hi. What do y'all use to put in your hot tub after you get out? we have been using Leslie's Fresh N Clear spa oxidizing shock, fast acting and chlorine free. Is there anything better and that comes in a larger size than what they have? Of course better price is good too! TIA


Well-known member
Feb 17, 2017
Dahlonega, Georgia
You didn't say if you are sanitizing with bromine or chlorine. Fresh n clear is potassium peoxymonosulfate, also referred to as monopersulfate, or MPS. I have a bromine spa, and was using MPS as the after soak oxidizer, but it's a little pricey. I switched over to using Walmart brand 8.25% bleach as the after soak oxidizer, and it works just fine. I have a bromide bank of at least 30 ppm in my spa, so the bleach converts the sodium bromide to hypobromous acid, the active sanitizer. This reaction happens quite quickly, usually in a manner of a few minutes, so the bleach does not usually oxidize the bather waste directly, but the formed hypobromous acid does. Needless to say, while bleach works as well as MPS, or maybe even better, it is quite a bit more economical to use.