Not having success with BBB in my hot tub

[chem geek]

Just an update. Decided to give CL one last shot. As Richard and I discussed, my CYA was high so I did a drain and refill and have the CYA at 30PPM now. Also gave up on the salt since Richard suggest that it oxidize the CL faster. Things appear to be much more stable after the refill. I can hold a CL greater than 6PPM for a day day or two now so maintaining the tub with CL is now tolerable.

Thanks for the update. The lower CYA level will keep the sanitation level of chlorine up while the elimination of extra salt (chloride ion) will cut down the outgassing of chlorine gas (it's not that it oxidizes faster, but that it gets converted back to chlorine gas -- the opposite of dissolving chlorine gas in the water).

As others have mentioned, using Bromine is quite typical in a spa so if you get frustrated with the chlorine just switch. Keep us posted, especially if anything changes (e.g. you experience hot tub itch, or you start to lose too much chlorine, etc.).

Richard

[tphaggerty]

My Softub requires the use of chlorine (not bromine) for maintaining the 5 year warranty (at least in the US, the Candanian warranty is different, I believe). The sanitizer they sell is Dichlor and they recommend replacing the water every 2 to 3 months because it becomes "unstable". Yeah, because the CYA levels go sky high!!

My 300gal Softub tested at over 100ppm CYA using the sight test after using DiChlor for about a month (one TBSP about 3 times a week). It was over 300 on the strips after 3 months of using DiChlor. Yikes!

Anyway, I too have decided to try BBB. I have found that about 1 to 1 1/2 oz of regular bleach will get the tub to 3 to 4 ppm and keep it above 2 for a day or so. The only problem I have found is that the PH seems to jump around more, but since I didn't start with "fresh" water (I had been using DiChlor for several weeks before testing then switching), I'm not going to worry until next fill. Then I will use Borax to hopefully buffer the PH better.

Anyway, so far the results have been good. Water is clear, no itch, no noticeable film on the vinyl. As Richard says, biofilms do get started in hot tubs and the only way to clear them is a pretty good shocking. I want to try this with a complete refresh of the water, but as of right now, my DiChlor is put away and I have a nice quart bottle of bleach and a measuring cup in my tub kit.

[CanuckPool]

I live in Canada and just got a 6 person SoftTub this year. The guide recommends the use of Bromine since it holds up to the hot temps better than chlorine, which is why I find it strange that SoftTub US doesnt want you using Bromine. My upkeep is super easy, just bring up the bromine reserves when you first fill it (5-6 ppm) and then use the bromine floater and adjust your PH every so often. I also have a "shock" which has a PH lock and a bunch of other stuff I put in once every week. I also squirt in a little clarifyer which is suppose to help with the filtering etc etc. not sure if it actually works. I too was told to dump the water every 2-3 months which I am about to do at the end of this month so I can do it again in Dec to try and bridge over till spring (I dont want to change 300 gals of water in the dead of a canadian winter)

But so far so good, I usually keep the cover on unless we are using it, so there is no worry about the sun breaking down the bromine levels quickly.

I heard somewhere that you were suppose to use unstabilized chlorine in a hot tub, not sure why or what that means.

[chem geek]

I heard somewhere that you were suppose to use unstabilized chlorine in a hot tub, not sure why or what that means.

The reason you heard that it is best to use unstabliized chlorine in a hot tub is because CYA (which is introduced with stabilized chlorine) reduces chlorine effectiveness. The bacteria that causes hot tub itch (Pseudomonas aeruginosa) is somewhat resistent to chlorine (and likes hot temperatures which is why it is found in hot tubs and not in pools). So not using CYA or at least keeping the CYA at lower levels allows for greater disinfection and prevention of hot tub itch.

Of course, if you don't use CYA, then you will lose chlorine very quickly if the hot tub is exposed to sunlight and you will even lose the chlorine more quickly in darkness due to greater outgassing (especially if you add extra salt to your hot tub, which you shouldn't). If you keep your hot tub covered most of the time, then you reduce the loss from outgassing.

So there is a tradeoff for how much CYA to use and I am not clear on exactly where the best level should be, but suspect it is on the lower side -- not more than 30 ppm.

Richard

[chem geek]

A P.S. to my last post above.

I have been told that many State health departments are now saying that no form of stabilized chlorine should be used in a hot tub, so that is probably where you heard this. Also, I heard that HTH has recently discontinued their Di-Chlor packaged for hot tub use and now only sells Cal-Hypo as a spa chlorinator and spa shock.

So the conservative approach would be not to use any CYA at all in the hot tub. I would say that if you find you can keep your chlorine levels stable so that you don't run out or get to low levels too quickly, then that would be OK. The very high disinfecting chlorine levels when no CYA is present will certainly kill off virtually everything including hot tub itch bacteria rather quickly, but will also fade (and degrade any rubber in) your swimsuits.

Personally, I think that the rule of using no CYA is a "black-and-white" "either/or" over-reaction to a real problem of having too much CYA. So I'm conflicted as to what to truly recommend. My gut feel (based on the information that I know) is that a small amount of CYA would be OK, but to keep it as low as possible such that it allows you to maintain chlorine levels (since running out of chlorine even with no CYA is obviously much, much worse). If your hot tub can maintain chlorine levels with an amount of CYA that barely clouds up in the CYA test and is therefore quite small (probably 10 ppm or so), then that might be a decent balance between chlorine disinfection and chlorine preservation, but I honestly don't know for sure.

Richard

[tphaggerty]

That was my plan. Use the DiChlor for the fill and maybe a couple more days to get a low CYA level, then switch back to bleach.

Canuckpool, I have the same tub! It is great, we use it all winter. NY isn't as cold as the Great White North, but all the kids love going out on a cold night and freezing their hair while staying warm in the tub! We have the cold package, which includes a 1" rigid foam board with reflecting layers that you put under the tub and a soft floating water cover that goes under the hard cover. Expensive, but it really helps keep the water warm and helps it heat up faster after being used. I just wish the tub would go 1 degree warmer.

The US warranty for Softub is very specific about using chlorine and only chlorine. Their product, called Chlor (cute), is DiChlor. I don't think they have a Cal-Hypo product. I have considered using bromine and damn the warranty, but decided to try BBB since I have all of the ingredients, thanks to POOLFORUM.

[CanuckPool]

Cool, yea we just got it this year, its the camel brown color (colour for us Canadians) with the blue water pattern and swirly tile top, it is actually the same liner as our pool, how coordinated! We only have the bi-fold top... should we look into getting all the winter stuff??? I guess I can find out this winter. It seems to stay pretty warm under the cover. I hear you about the heat level, after sitting in it for 5 minutes you get used to the heat and want it higher. Too bad there wasnt a 106 level! I guess since the method that it uses to heat the tub (via motor heat) it cant go above 104.

Sorry to hi-jack the thread a smidgen.