Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 4 of 4

Thread: Disinfecting spa??

  1. Back To Top    #1

    Join Date
    Dec 2008

    Disinfecting spa??

    I can't seem to find the article on here for disinfecting a hot tub, does anyone know where it is?

    Also would I be able to do disinfecting of the used tub with regular bleach but at a higher concentration of bleach or even sodium bromide? I was reading another site to use dichlor?

    We are very close to getting it up and running but I would like to do a fill, disinfect it for like 30 minutes while running and then throw in a spa flush and circulate for a bit... would this be feasible?
    "Sometimes you have to look reality in the eyes and deny it." --Unknown

    2003 Marquis Reward 6 person spa/320 gallons/2 filters/ozonator (unknown if it still works, the ozonator that is.)

  2. Back To Top    #2

    Re: Disinfecting spa??

    most spa flushes are enzyme based and would be destroyed by high chlorine levels. If you want to disinfect do that after the flush and refill. Just shock the spa and then let the chlorine level drop. You would want to bring the FC up to about 30 ppm to 50 ppm if you suspect that the spa might have harbored pink slime or white water mold. Sodium bromide is NOT a sanitizer but the precursor to hypobromous acid, the bromine sanitizer. It does not become active until you add an oxidizer such as chlorine.

  3. Back To Top    #3

    Join Date
    Mar 2007
    San Rafael, CA USA

    Re: Disinfecting spa??

    You might be referring to the the 1998 “Spa Decontamination Procedure” in the Information Bulletin from the International Aquatic Foundation, Alexandria, VA. This post on another forum and PDF file pages 56-59 (51-54 in page numbering)this PDF file describes that procedure, but keep in mind that this is for commercial/public spas so is a rather extreme procedure. I shudder to think what 100 ppm FC of unstabilized chlorine would do (and you wouldn't want to use that much stabilized chlorine either since the CYA would get too high), but at least the exposure is relatively brief. Note that the bulletin has no clue as to the difference between using unstabilized vs. stabilized chlorine (they list both hypochlorite sources and Dichlor) so I would be very wary. What waterbear describes is more than adequate for a normal residential spa situation.

    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
    12 Fafco solar panels; Purex Triton PowerMax 250 natural gas heater (200,000 BTU/hr output); automatic electric pool safety cover; 4-wheel pressure-side "The Pool Cleaner"

  4. Back To Top    #4

    Re: Disinfecting spa??


    I wondered about that decon process of raising FC to 100 ppm using bleach with no CYA present. That would be quite a potent mix. I guess ths better route would be to shock with Dichlor to say 50 ppm, then shock with bleach the rest of the way to 100 ppm.

    When I did my two decon procedures. One tub owner was using Triclor the whole summer. There was probably tons of CYA present. The 100 ppm FC from the bleach probably didn't do a thing. He closed it for the winter, so I may recommend doing it again in come spring. The other tub owner was using Dichlor, but once a week. His CYA was probably in a good range.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts