About Hot Tub Contamination
||Well-maintained spas are easy to keep clean
and healthy. However, if neglected over time, a
persistent contamination problem which is hard to correct may
result because of the formation of slimy
biofilm containing mold,
bacteria, and other microorganisms.
Some signs of problem spas include: slime
formation, cloudy water, and foul or musty odors. Another is skin rashes, which may take several days to develop, and which are suspected to have originated from spa
If the spa water has become severely
contaminated, the plumbing system and filter may be harboring excessive amounts of bacteria
in biofilm which may be resistant to your normal
sanitizing methods. If you suspect such a problem, have purchased a
used spa, or are returning a spa to service after a period of neglect,
decontamination procedures should be followed as a
precaution, since normal draining, cleaning, and replacement of
the spa water may not completely correct it. Decontamination is also a good
practice when switching to a new or alternative
Fortunately, there is a disinfection procedure
which can bring a sick spa back to good health. This corrective action involves three basic phases:
Phase 1 - Decontamination
- Water replacement
your spa cover, paying special attention to the underside, using
Clean All Spray. Then be
sure to seal it with
to help discourage new mildew formation.
If hot tub cover is in bad condition or waterlogged, it
should be replaced. A waterlogged cover will likely be infested
with mold, mildew, and bacteria, and may continuously inoculate the spa
water with more microorganisms. If you need a new hot tub
cover, consult the
Cover Replacement Guide.
After cleaning and rinsing filter, completely submerge
the cartridge in a strong solution of
Chlorine in a clean plastic bucket (use about 1 teaspoon Dichlor in 3-5 gallons of water). Soak
for 2 to 4 hours. Also inspect and clean the interior of
the filter housing and skimmer.
Hot Tub Vessel Superchlorination
Now that the cover and filters have been
addressed, we can focus on the spa itself. Using the dosage
superchlorinate the spa water to at least 100 ppm
Dichlor Granular Chlorine which has been
first pre-dissolved in a plastic bucket of water.
Pre-dissolving the chlorine will prevent possible damage
to your spa's acrylic surface from direct contact of
chlorine granules. (The table is provided since 100
ppm is too high to be measured with test strips).
Dichlor - 100 ppm Dosage
||2 1/2 oz.
||4 3/4 tablespoons
||6 1/4 oz.
||12 1/2 oz.
||1 1/2 cups
Now raise the water
level in the spa to about 1/2 to 1 inch above the normal
high water mark. Circulate the spa water at high speed for
30 minutes with spa cover closed. Make sure jets are on
maximum. Turn air injector switch on and then off for 5
minute intervals during this process to help disinfect air
lines. If your spa is equipped with an electric air
blower, run it for a minute every five minutes.
inhalation of vapors or mist from spa during the decontamination
Flushing Spa Plumbing System
||Next, and prior to draining, add
System Flush per label directions. Allow water to
circulate for an additional 30 minutes, continuing to turn
air injectors and/or blower on and off at above
System Flush is important, as it breaks up and
flushes away inaccessible oily deposits, dirt, and other debris from
your spa's internal plumbing system. Completes the
cleaning process from the inside out.
Phase 2 - Water Replacement
cleaned and sanitized filter, or better still, a new filter cartridge.
Refill the spa with fresh water. Now balance the
water, paying close attention to Total Alkalinity and pH. Refer to
Prep & Maintenance guide.
Fill your hot tub with Cleaner Water
The Pre Fresh Spa Filling Filter reduces many impurities, including odor causing organics. Beginning with pure water reduces demand on your spa chemicals. Highly recommended for well water users or when source water is questionable.
Do not add your
sanitizer at this time, but proceed to Phase 3.
Phase 3 - Verification
The final, and
perhaps most important step is verification of
decontamination. Understand that contaminants place
a demand on, or deplete free chlorine residual. Now
shock the refilled spa with 10 ppm of
Chlorine, pre-dissolved in a plastic bucket of
|| This is approx. 1 1/4 oz. (2 tablespoons) per
400-500 gallons. Check the spa water with
Test Strips to confirm approx. 10 ppm.
Allow the spa to
circulate for 8-12 hours with spa cover in place to avoid
sunshine degradation of the chlorine level, or circulate
overnight if spa is uncovered.
circulation period, check the free chlorine level with
Test Strips. If you get a residual free chlorine
reading on your test strips, decontamination was likely
successful. If no free chlorine residual is present,
excessive demand may still exist, indicating that contamination
is still present and depleting the chlorine. So, if no free
chlorine is present, repeat the decontamination procedure.
After successful decontamination
has been verified, add the sanitizer system of your
choice. (Any residual chlorine will normally deplete in a few
days, and is compatible with all of the sanitizer systems that
we offer). Maintaining your sanitizer, and using
Flush with every water change will help prevent the
need for a total decontamination again in the future.
residual chlorine is above 5 ppm after verification, reduce it
to 3-5 ppm by draining a portion of the spa water and replacing
with fresh, or allow chlorine to dissipate naturally prior to
using the spa. If you want more information on the various
sanitizer systems available for your spa, refer to our