Decontamination (How to Super Shock your tub)

[Nitro]

This topic comes up quite a bit, so I thought I'd post a How To guide.

Decontamination is the process of Super Shocking to Kill and Oxidize everything in your tub. There are two reasons why you would want to do this. One is your tub contains an excess amount of organic waste, and is using large amounts of sanitizer. The other is you have bacteria actively growing in your tub that has formed a protective shield (Biofilm), and cannot be killed from normal sanitation levels. The former is easy to tell by measuring sanitation levels, but the latter is more difficult (usually not until after you start getting sick).

This may sound extreme to some, but I recommend decontaminating any used tub that changes hands. You have no way of knowing how a used tub was maintained before you got it. Why chance getting sick?!? You have nothing to lose, and nice clean, safe tub to gain.

So how do you do a decontamination?!? Here's how.

1. Use an enzyme to clean out your pipes, such as Swirl Away, Spa Flush, Spa Purge etc. Add this product, run the jets 30 mins and let sit overnight. It will clean out your pipes and deposit the gunk along the water line. Wipe the waterline with a dry paper towel or cloth. Make sure you remove your filter before adding this product. Better yet, buy a new filter.
2. The next day, drain your tub and clean the walls with some leftover enzyme from step one.
3. Refill tub as high as possible (above the normal waterline) with fresh water.
4. Balance your water at this point. TA = 80 ppm and pH = 7.2. If your pH is too far out of range, it will decrease the effectiveness of the Chlorine.
5. Add 50-100 ppm FC using Regular Clorox 6% Unscented Bleach. That's approx. 1/4-1/2 gal (32-64 oz) per 350 gal tub.
6. Run all jets and air features for 30-60 mins. You can turn the air on and off every 10 mins, to help clean the air lines.
7. Cut the power and drain the tub. This water is highly chlorinated, so you may want to keep it away from vegetation.
8. While the tub is draining clean the cover and all shell surfaces with the super chlorinated water. Then rinse well.
9. Refill tub with fresh water.
10. Balance water.

Test your Chlorine Demand to make sure the Decontamination worked by doing the following.
11. Shock with Dichlor (Stabilized Chlorine) to 10 ppm FC. Don't use the tub, let the jets run 10 mins, cover and let sit 24 hours.
12. Check FC. If FC is 5 ppm or above, you're ok. If it's zero, your tub is still using excess Chlorine, and needs to be decontaminated again (Absent the Spa Flush). However, this should be rare.

After this procedure your tub should be clean like new. If you maintain your water properly, your should never have to do this again.

Happy Clean Tubing!  

[Chas]

Here is the method I have posted many times over the years. I got it from Watkins MFG and it will clean out a tub with all sorts of nasty bugs - notice it doesn't include the swirl away.  I personally only recommend that when a tub is being switched off of Baqua.

[size=12]Procedure for Chemical Cleansing[/size]

Filters:
1. Cartridge Filters: Remove the filter cartridge(s) and either clean or replace. To clean cartridge(s), first use a filter cleaner as per label directions. After rinsing the filter cartridge(s), completely submerge the cartridge(s) in a 1/10 solution of sodium hypochlorite (liquid bleach) and water for two hours. Inspect and clean the filter housing. Set the filters aside for installation after the spa decontamination is complete.

    * Warning: Contains sodium hypochlorite.
      Causes substantial, but temporary eye injury.
      Harmful if swallowed.
      May irritate skin. Do not get in eyes or on clothing.
      For prolonged use, wear gloves.

Note: Baqua users (Biquanide) drain and refill spa before adding any chlorine.

2. Raise the water level in the spa 1/2 inch above the high water mark, and remove pillow if possible.

3. Turn on the jets - all of them - let them run for one hour.

Superchlorination and Neutralization:
4. Add at least 100 ppm chlorine to the spa being sure not to allow the Dichlor to come into direct contact with spa surface before is dissolves.

    * Sodium Dichloroisocyanurate - 56%
      6.25 ounces per 250 gallons,
      8.75 ounces per 350 gallons,
      12.50 ounces per 500 gallons.

5. During Superchlorination, be sure to rotate any diverter valves or other systems to allow water flow through all jets and systems for at least 5-10 minutes in each position.

6. For the first 60 minutes, do not cover the spa with the spa cover.

7. Neutralize the chlorine in the water with 16 oz of Hydrogen Peroxide (3%). Test for chlorine: more Hydrogen Peroxide may be needed.

    * Warning: Hydrogen Peroxide, 3% U.S.P.,
      For external use, topically to the
      skin and mucous membranes.
      Keep out of eyes.

8. Circulate the spa water for 10 minutes, during the Chlorine neutralizing process.

9. Stop circulation by turning off all jets.

10. Drain and flush the spa.

11. Clean the spa surface with a surface cleaner approved for you type of spa shell surface. Rinse the spa thoroughly!

Water Replacement and Treatment:
12. Refill the spa with water, reinstall the filter, which has been sanitized (or replaced).

13. Follow the startup procedure for your particular spa. Balance water chemistry before use.

14. Clean the cover thoroughly using an approved vinyl cleaner. Rinse the underside with a dilute chlorine mixture and rinse well.


 8-)

[Nitro]

I recommend Swirl Away, because it's easy to do and why not? If you're going to go through the process, you might as well go the whole nine yards.

The main difference with your method and mine is the use of Dichlor as opposed to Bleach. I recommend Bleach becuase it doesn't contain CYA. If you add 100 ppm FC using dichlor, you're also adding 90 CYA. That will reduce the effectiveness of the Chlorine by a large amount.

An Active Chlorine of 100 ppm FC and 90 ppm CYA using Dichlor, would equal ~15 ppm FC with 0 ppm CYA. That means by using only bleach it's ~6 times more potent. That means 20-50 ppm FC Bleach would probably be plenty. However, either way both should be enough to kill anything off.

The other reason I recommend bleach is because it's cheap, easy to get and use. If you're going to drain the tub anyway, why waste the Dichlor.

Neutralizing the tub with HP might be a good idea if you're worried about draining super chlorinated water near vegetation. However, I drained a tub with 100 ppm FC and 0 CYA in unwanted grass and weeds, with no harm. Unless you have local ordinances against it, I wouldn't worry about it.

[hottubdan]

Watkins posted those instructions before the flush products were on the market.  We sell Spa Purge from Natural Chemistry.

[Hillbilly Hot Tub]

As a note, to kill crypto, you must maintain chlorine levels at a minimum of 20 ppm for 12.75 hours, If your chlorine level is at 10 ppm it takes 25.5 hours and if it is at 1 ppm it takes 255 hours. When we do a decontamination we leave the water in for 24 hours to be safe. Crypto is getting harder to kill.

I am not sure if you raise the ppm to, say 40 if it would take 6 hours and so on. If someone knows let me know. I was taught for pools and 20 ppm is more managable to reduce than 100 ppm.

[Nitro]

HHT,

20 ppm at what CYA level? CYA of 18 ppm would be the same as adding Dichlor? However, as you know there is quite a bit of difference between adding Dichlor, and straight Bleach. Using Bleach is ~6 times more potent than using Dichlor. i.e. 15ppm FC Bleach = 100ppm FC Dichlor.

[TubsAndCues]

I recommend Swirl Away, because it's easy to do and why not?

Because it is incompatible with biguanide systems like BaquaSpa and Soft Soak.

Swirl Away is a great product, but you need to make sure who you recommend it to.  Granted, I understand we are talking about chlorine based tubs in this section, so I'm not disagreeing that it doesn't hurt.

I personally have switched over to using Spa Purge instead.  Same end result, if not better IMO.  It takes longer (24 hrs) and you have to have the tub up to temp before you add it, but I really like the stuff.

I recommend to my customers that they use Purge once a year, same as I do at my own house.  The results have been fantastic, and for someone like you, Nitro, that watches your chlorine consumption so closely, I'm sure you'd agree that it helps.

[Hillbilly Hot Tub]

HHT,

20 ppm at what CYA level? CYA of 18 ppm would be the same as adding Dichlor? However, as you know there is quite a bit of difference between adding Dichlor, and straight Bleach. Using Bleach is ~6 times more potent than using Dichlor. i.e. 15ppm FC Bleach = 100ppm FC Dichlor.

This is the NSPA guidelines for pools. They do not state at what CYA level, but since the guidelines call for you to have a 20-30 CYA, I am going to say thats what they are going by, and they are using sodium hypo 12% to raise the level.

Guidelines for spas is the decontamination procedure I printed from the CDC in the other forum which is much of the same information you printed, basically raise to 100 ppm, keep going out and turning air/jets on for the next 24 hours and drain.

[Hillbilly Hot Tub]

This is the NSPA guidelines for pools. They do not state at what CYA level, but since the guidelines call for you to have a 20-30 CYA, I am going to say thats what they are going by, and they are using sodium hypo 12% to raise the level.

Guidelines for spas is the decontamination procedure I printed from the CDC in the other forum which is much of the same information you printed, basically raise to 100 ppm, keep going out and turning air/jets on for the next 24 hours and drain.

Swirlw away is compatible with all sanitizers, even states it on the bottle. I know leisure time jet clean is not compatible with Baqa, but swirl away is fine.

[TubsAndCues]

Swirlw away is compatible with all sanitizers, even states it on the bottle. I know leisure time jet clean is not compatible with Baqa, but swirl away is fine.

Good to know.  We (both the company I work for as well as myself personally) switched a few years back because it didn't used to be.  Said that on the bottle as well.

Might have to give it another shot.  It was definitely easier due to less time required, but I still like Spa Purge.  Always worth trying it again to see if it's any better or worse now that I've had some good experience with the Purge.

Thanks for the info, HTH!

[Nitro]

Because it is incompatible with biguanide systems like BaquaSpa and Soft Soak.

Swirl Away is a great product, but you need to make sure who you recommend it to.  Granted, I understand we are talking about chlorine based tubs in this section, so I'm not disagreeing that it doesn't hurt.

I personally have switched over to using Spa Purge instead.  Same end result, if not better IMO.  It takes longer (24 hrs) and you have to have the tub up to temp before you add it, but I really like the stuff.

I recommend to my customers that they use Purge once a year, same as I do at my own house.  The results have been fantastic, and for someone like you, Nitro, that watches your chlorine consumption so closely, I'm sure you'd agree that it helps.

As HHT mentioned, Swirl Away is compaitble with biguanide. Regardless Biguanide (or anything) will not stand a chance against this procedure. The 100 ppm FC of pure bleach on the second fill should wipe out anything and everything.

Yes, I do recommend purging your pipes once a year. However, assuming you maintain your water correctly, you should never have to super shock your tub again.