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After reading back a bit I can neutralize the chlorine hydrogen peroxide. How much would I need to add to lower from 60ppm in a 165 gal spa? I can do that when I get home tonight and drain Monday.

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It takes roughly the same volume of 3% hydrogen peroxide to neutralize that volume of 6% bleach. I'd use somewhat less since it's OK to have a lower amount of chlorine in the spa and that will keep it sanitized. If the chlorine went to zero, that would defeat the point of decontamination. Use half the amount, mix and wait 10 minutes, then retest and see where you are at and add more accordingly. Just get it down to around 3 ppm FC and you should be OK.

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Excellent info for decontamination, Nitro!!

I was going to drain my tub to do some maintenance and possibly switch from bromine to N2.

To my horror, I found some flocculation in the footwell when the pumps cycled off.

Per another thread, I got some bad gouge from the dealer on using running the bromine low due to the installed CD ozonator.

I've found some good water chem threads on this site that show what the ozone really does (oxidizer vice sanitizer).

I reviewed Nitro's Decon procedure and followed it. It works great.

As expected, my filters were well bleached.

I ran 45 oz of Clorox in my 500 gal tub.

I would like to see the hydrogen peroxide neutralization step added for environmental reasons.

In my case, I have waterfront property, so I don't want to bleach the creek and associated vegetation and draw the ire of the Lorax or the Department of Natural Resources.

I found the ratio (1:1 of 3% H2O2 to 6% Clorox) in another thread and bought enough to put 45 oz of peroxide into the tub before draining the superchlorinated water.

Proof that it works:

As I have a titration kit on order, but not on-hand, I have to go with my test strips.

The Cl/Br color went immediately deep purple (pegged on FC) for the superchorinated water.

With all the jets running, I slowly added the peroxide in the center of the tub and let the jets go for another 10 min.

I plunged a second test strip in the water and did not register any FC.

Also, the chlorine smell was totally gone.

In addition to the ratio, I would put an advisory statement that the peroxide reduces the bleach to salt and O2.

In a contained area (enclosed plumbing, etc) a violent reaction may occur.

Poured into the center of an open roiling tub with the jets running, one will merely see more bubbles as the O2 comes out of solution.

Currently on the refill and reestablishing my bromine tub per Waterbear's 3-step program.

-Matthew

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Thanks for the info and suggestions which are all good. Just note that if you overdo the hydrogen peroxide and have any leftover after the drain/refill, that you could have some oxidizer demand and need to use more before you get a reading.

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Very true and most likely happened in my case.

I questioned that in a different thread concerning reaction time of the bromide oxidizer.

I was concerned about the efficacy of my MPS since it didn't seem to light off following the post decon fill.

The other possibility was residual H2O2.

Once I hit the tub with the equivalent amount of 6% Clorox to oxidize the NaBr, I got a Cl/Br reading that pegged the strip (titration kit hadn't arrived yet).

The next time around, I will start with 1/2 to 2/3s the required amount of H2O2 and work up to an amount that gets the Clorox down to a trace amount.

I may also want to add a "rinse" step that refills the footwell to allow the pumps run briefly and expel the water in the plumbing without cavitating due to lack of scavenge.

That should allow me to be thorough without going Rube Goldberg and still be respectful of the watershed in which I reside.

-Matthew

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Just out of curiosity, where you suggest let it sit overnight, does that mean kill the power to the tub as well or just let them run as normal through the night?

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my water was mostly balanced when i started the super-chlorination step (fresh fill). TA was a little low around 20-40 and the ph was about 7.0 (had to use test strips since my taylor kit is still in the possesion of UPS). What i wasn't expecting because i hadn't seen it noted here was that the pH would go off the scale high as soon as i added the bleach (8.4 being the high for the test strip). I tried reducing it for a bit but just gave up knowing i was going to dump the water in an hour anyway. I neutralized it with H2O2 before dumping and the pH came back down as the bleach neutralized. i assume this is normal and the high ph didn't harm the effectiveness of the decon?

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High chlorine or bromine levels can cause a chemical interference with pH testing and cause it to read high when it really is not. Do not try to test or adjust pH fi the sanitizer levels are above 10 ppm (3 ppm in some less expensive test kits.

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Also, the pH does rise when you add the bleach, but for the decon procedure that's OK, especially since you started out lower in pH. And as waterbear noted, then high FC will interfere with the pH test anyway giving you a falsely higher reading.

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Hi - I'm new to this forum and hot tubs in general and was hoping for additional clarification on a question that had been asked but never really answered

I would like to follow Nitro's decontamination regimen since I just came into possession of a used hot tub. The instructions has Swirl Away and Shock as two separate fill and drains. Is there a reason why I can not fill the tub, run the Swirl Away overnight, super shock the next day and then drain completely? I understand why you can not Shock first as that would interfere with the enzymatic action of Swirl Away not why would it not work the other way around?

I apologize in advance if this has been answered elsewhere. Thanks!

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First, I'd use Spa System Flush since people find it to be better than Swirl Away in most cases. Second, yes you could use the Spa System flush and after waiting the appropriate time you could then decontaminate with a high chlorine level. The main reason for doing them separately is that the Spa System Flush for a new spa often brings out a lot of material (it is a surfactant that dislodges biofilms and grease) that you'll want to dump rather than have chlorine wasted on trying to oxidize it since the purpose of the superchlorination is mostly to decontaminate and kill off any remaining bacteria.

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Thanks Chem Geek!

I ran Swirl Away through the system yesterday evening and let it sit overnight. Some bubbles at the top but no real "goop" or anything else to speak of! Will continue the superchorination today and hopefully post my water results for some help in continuing with my water chemistry!

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I have a few questions if i may:

  1. I'm not sure if the same flush products are available in the UK as in the USA, but any recommendations between PureSpa Spa Flush and JetOne flush? Or anything else recommended? I can't seem to find the SeaKleer Spa System Flush over here. I'll avoid Swirl Away as it seems it's not recommended?
  2. Do you take out the filters when adding the flush product? or do you add it, run jets for 30 mins and then take filters out overnight? bit unclear on this part
  3. If you add bleech to 50 ppm for the decontamination, is this just normal bleech like you'd buy from a supermarket? anything to avoid? (other than the lemon scented bleech etc :))
  4. Can you use dichlor granules instead for the super chlorination? - any negatives or positives other than presumably it being more expensive? how much would you need to add if you did use dichlor instead?
  5. When you have super chlorinated the water, do you run the jets for 30 - 60 minutes with the cover on or off? I know normally when you shock you would do with cover off to release gases and avoid staining the underside of the cover, but do you do it differently here to help decontaminate the cover?
  6. Do you run those jets with the filters in or out? presumably back in....any negatives in that if you've done the system flush, and then the super chlorination without emptying in between?

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You can also add hydrogen peroxide to quickly lower the FC level. Every ounce of 3% drugstore peroxide (10 volume) will eliminate approx 1.5 ppm chorine (or equivalent bromine).

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It turns out that roughly the same volume of 3% hydrogen peroxide dechlorinates a similar volume of 6% bleach. The 1.5 ppm FC per ounce of 3% hydrogen peroxide would apply to a roughly 350 gallon spa. Proportionately more would be needed for a larger spa, etc.

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1. I don't know anything about the two flush products you mentioned and unfortunately reading about them doesn't help. Swirl Away is not bad; it's just not as good as Spa System Flush. The ingredients of Spa System Flush are not disclosed, but are probably powerful surfactants. Both products you linked to sound OK, but one never knows until one tries. There was nothing obvious about Swirl Away not being as good as Spa System Flush, but once we had quite a few reports of one being better than the other, we just recommended one over the other.

2. You follow the instructions on the flush product and I believe they recommend removing the filters when using the product (see this link for SeaKlear Spa System Flush instructions, for example).

3. The bleach is 6% regular bleach. Not scented, outdoor, easy-pour, etc. since those have scents or thickeners in them you don't want. You may need to get "Ultra" bleach to be at 6% since some brands of "regular" bleach are 3% or less.

4. You can use Dichlor instead of bleach if you want to and raise it to the same 50 ppm FC in both cases. It's just more expensive. It turns out that the active chlorine level either way is fairly similar because the bleach causes the pH to rise a lot while the Dichlor causes the CYA to rise a lot. Both effects moderate chlorine's strength.

5. For decontamination, always run with the cover off. If you need to clean the cover, do so separately with a dilute bleach solution or a specialized cleaner and then rinse with water when done. Usually you don't need to decontaminate the cover -- it's not usually where biofilms form even though it is usually moist. For whatever reasons, biofilms mostly form just above the water line and in piping (at least when chlorine levels are low-to-zero for too long). Above the water line is easy to wipe. Piping isn't, which is what the Spa System Flush and super-chlorination are for.

6. I would keep the filters out for both Spa System Flush and for superchlorination. You can clean the filters separately with detergent solutions (or with trisodium phosphate, TSP) or you can replace the filters, depending on how old they are. See this post for info on cleaning cartridge filters.

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thank you Chemgeek for the reply and thoughts

I guess i'll explore what flush products are available in the UK a bit more in case i can find the Seakleer brand. if not, I'll have to try one of the others.

I guess my question about removing filters was only because hot tub manuals seem to suggest you should never run the jets with filters out, presumably because stuff can get into the pipe work? If thats what is recommended for flush products (and for the deconatmination step) then i suppose it must be ok :)

I'll have a look for bleech although give it only needs about 20 ml of Chlorine for a 10 pppm shock at the moment, giving a dose of 100 ml to reach 50 pppm isn't much in the way of chlorine anyway. maybe I'll go that route for ease.

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Hi,

I'm also brand new to owning a spa, and haven't found the local dealer super helpful. I bought a used Artesian Spa and would like to decontaminate it following the directions in this thread.

My question is the Spa's manual has a strongly worded warning saying "Never run the spa without the Filters Installed!" It doesnt explain the reasoning behind this warning. The directions in this thread, and on the Spa Flush bottle I purchased advise removing the filters during the process. So, Is it safe to run the spa without the filters installed? I just want to make sure it wont cause any damage to the internal pumps, etc. by running it without filters for this process. I purchased new filters that I plan on installing once the decontamination process is over anyway, so i dont know if there is any downside to leaving the old ones installed until the decontamination process is complete?

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Kevin,

The filter serves 2 purposes:

-It removes solid particles that are greater than the pore size (hair, dust etc) to keep the water clear of those items

-It protects the pump impellers, plumbing and jets from FOD (foreign object damage) such as twigs, bark chips, acorns that the &^$*& squirrels try to drop into my tub and anything else that might have gotten in there.

I would recommend that you fill the tub and run it with the filters in place to ensure that anything that comes out of the plumbing doesn't get sucked back in. Skim/clean out any debris, remove the filters and start the Decon procedure with your cover on to prevent FOD from dropping in the tub during the 1 hour run or the overnight soak.

If you are replacing your filters (and you should for a newly acquired tub), then leave them out for the superchlorination run.

If you are not changing the filters (quarterly drain/fill) then leave them in with the chlorine to sanitize them as well.

You don't need to sanitize new filters.

If you follow the above and leave your cover off for the superchlorination (which you should), then your tub and plumbing is technically exposed to potential FOD during the run. I've gotten an acorn or two during that run, but they never make it past the jet pump intake screens in the footwell.

The Decon procedure and superchlorination procedures work.

If you are in an environmentally sensitive area (which can include your yard), the extra gouge about neutralizing the 50ppm Cl with hydrogen peroxide works. I add half the recommended amount, hit the jets and then gradually add it until I'm down to about 1-2ppm before I drain to ensure no residual peroxide when I set up the Bromine bank.

Hope that clarifies your thoughts as you clarify your tub.

-Matthew

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ive just finished carrying out this process. i managed to get hold of some SeaKleer Spa system flush and so added about half the bottom and left jets on for 60 mins. it left a brown scum line round the edge of the waterline which was "pleasing" in so much as i know it was cleaning the pipes well. i wiped this away with a paper cloth which was fine. let it sit overnight for 12 hours and then added the chlorine treatment to 50 ppm. left jets running again for 30 mins and another brown line (smaller) formed which i also wiped away. have just finished draining and cleaning and am now filling it up again to start nice and fresh :)

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I am in the process of decontamination and just have a quick question.....after turning off the jets after letting them run for 30 minutes should I cut power to the spa while the swirl away sits over night or let it continue to run until tomorrow?

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Unless the instructions say to turn off the pump, I'd keep it running at its normal circulation, but it may say not to leave it in for more than a certain period of time. See http://www.poolspaforum.com/forum/index.php?showtopic=23260'>this thread for more info and note that since that thread it does seem that Spa System Flush often does a better job than Swirl Away.

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