dlleno
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Posts posted by dlleno
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All the evidence including your Cl measurements point to the fact that you are running your spa with active organic contaminants present in your equipment/pipes. Clear water is not proof positive of a contaminant -free spa. Even with Ozone running 100% of the time you should still have measureable Chlorine after dosing to 5ppm and waiting 24 hours. your decay rate is proof that you have bad guys eating up chlorine.
Honestly 2 years ago I would not have given this advice, I would strongly encourage you to purge with ahh-some.
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Thats it -- I'm switching to iodine. hah hah hah!!
nice info. One downside of a bromine spa is that you can't use a "non bromine" shock, as the oxidizer will generate bromine from the reserve. Unlike a Cl spa, where you can shock with MPS - or shock with Cl but accelerate Decay with ozone.
As a practical matter, we haven't heard of any real danger posed by a bromine spa, but this info does give one pause. I'm just not able to translate this into, say, an equivalent drain interval (suppose you could drain the bromine spa more often and approach the equivent toxicity of Cl), because you would have to apply the factor of 100!.
So -- what happens to these DBPs over the live of the water -- do they simply accumulate?
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OK please do let us know the results of your fc decay rest. On the subject of this being a new spa.... This is exactly the issue I faced with my new spa. It was delivered with active contaminant biifims which ate sanitizer. You have to at least, at the very minimum, shock your first fill with 10ppm or higher, and it's best to combine that with an ahh some purge. Thus is just the evidence from my experience
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Glad to be of help. Just another point that was implied but not stated outright: MPS, dichlor, Bleach -- they all result in a bromine conversion with their own respective differences (however small they may be) which is why I change oxidizers from time to time.
really liking the above plan -- and the regular Ahh-Some purge at drain time is not nearly as painful as it might sound, and reaps great benefits! Its just part of my routine now. I wish folks could see what is lurking in their pipes even when things are maintained well. Especially revealing to me was the discovery that filters need the Ahh-Some as well.
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glad you chimed in here Chem Geek-- now I'm going to have to experiment with FC decay rates with ozone, next time I fill and before I convert to bromine.
For the FC decay test itself, though -- what can be said about the contribution of ozone to the measured FC decay over time, under otherwise ideal conditions, i.e. no bather load, spa covered, etc? how much more quickly do you think FC will decay with ozone in use, compared to without ozone? I suspect we'd have to make some broad assumptions about the ozone concentration that might be commonly achieved in todays portable spas. It would be helpful for folks with CL spas with ozone, to be able to conduct a meaningful FC decay test.
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Well... my point is that you didn't fix the sludge and foam problems you only hid those symptoms, although I acknowledge that there is no harm in using a "foam down" type product if you are certain that the root cause is detergents and what-not from bathing suits or whatever.
the greenish water color could be due to copper, so I would suggest if you are committed to saving (rather than purging) your water then you should consider having it tested at a trusted local pool/spa store that has metals testing capability. It could also be a contaminant. such as algae, although is really hard to make such a diagnosis without further information. If additional chlorine treatments help with the color, then you still may be only hiding that symptom too, and I would not want to be in that water, given its history.
what is your FC decay rate now, with the spa covered? By the way, if you can turn ozone off I recommend doing that for the FC decay test, as ozone eats FC (at what rate is hard to predict.. It depends on the OG and I havent experimented with mine). Still, with ozone running and the spa covered (no jets running) your FC decay rate should be no where near what you reported earlier (5ppm to zero in 5 hours. my mistake for calling out 30 min). The only way to achieve that kind of FC decay is with a contaminant load -- and if you don't have good guys (bathers) in the water that means there are bad guys in it.
YOu asked a question earlier that wasn't answered -- the N2 is a silver ion based sanitizer suppliment, which can help with water maintenance but which can NOT keep up with a bather load and is NOT EPA approved without the addition of MPS or FC. Basically, is not a bad idea, and can help keep the water clean especially when you aren't using the spa for long periods of time. BUt it is frequently mis-understood due to heavy marketing and sales. too often, folks end up trusting it and relax their water maintenance program and end up with bad/contaminated water.
ALso -- I should have asked for clarification on this point: you said you are a new spa owner but didn't specify if your spa itself was new? is this a new spa or just new to you?
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well, first of all, dichlor is a good source of spa chlorine no question there, but your FC decay rate is too high, you've let the FC level go to zero, you've never shocked above 5ppm, you have green colored water. foaming and brown sludge, and suspected high bather contaminants/soaps and what have you. I just don't think there is any more analysis paralysis to accomplish here -- I'd say you need a purge/decon
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just an additional comment about combining the purge and the decon when Ahh-Some is used. this stuff is profoundly effective, as my own head-to-head experiments have shown. Other products release "little to nothing", such that one is tempted to combine the decon with the purge. not so with Ahh-Some!
Lagreca : here is what I do to get the gunk off the waterline: Ahh-Some itself is a great solvent for this stuff. fill a 5-gal pail with ahh-some treated water. as the stuff accumulates, wipe it up with a micro-fiber cloth and rinse in the Ahh-Some solution.
It turns out that Ahh-some is immune to the problem of combining the FC decon with the purge, as it is not an enzyme product. in fact ,as the above post indicates, the Ahh-Some instructions specify elevated FC levels during the purge, just to insure proper kill of the gunk Ahh-some releases. however, the amount of material released by Ahh-Some can be so great, you won't be very anxious to wipe down your spa and cover with the water ... The solution to this problem, my experience has shown, is to drain and purge again with Ahh-Some until you achieve little to no new released material.
The point remains, however, is that you SHOULD dose with a high FC level when treating with Ahh-some. When performing a purge/decon procedure I can say from experience that more than one Ahh-Some purge may be required, and by the time you achieve a clean spa -- where Ahh-Some releases very little or no new material -- that's the point where the combination of ahh-some dose and high FC will provide the best decon solution for the wipe-down. It does take some experience with Ahh-Some and a biofilm contaminated spa to really see this.
I've been there. I have also achieved an Ahh-Some dosed spa, with ceramic filters installed into their normal positions -- generating no new contaminant release. Arguably the cleanest spa known to man.
Another benefit of Ahh-some, which I have verified in my own experiments, is that regular purging -- and I mean every fill -- is beneficial. I routinely dose with Ahh-Some and ~10 ppm FC before draining, and every time I see visual evidence that I'm doing the right thing. Beyond the biofilm removal claims of Ahh-Some, this stuff will release material you would not imagine was in your spa -- even with proper water maintenance. this comes from build up of non-oxidized wastes/oils/what-have-you ...
I will take the liberty to re-summarize my experimental product test results here:
SeaKlear "System Flush": does a little, but not much
Silk Balance "Clean Start" worthless -- its just borax in a really expensive container
Aquafinesse "Spa Clean": worthless
Natural Chemistry "Spa Purge" . Epic amounts of nearly-worthless foam
Unique Solutions "Ahh-Some": woh baby this stuff works!
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a 5ppm shock 2 days in a row is not harmful at all, as that is not even a shock. What are you shocking with, that yields 5ppm FC? that's barely above safe bathing levels, (1-3ppm). Now a 100ppm shock is quite another matter -- don't be doing that every day!
The larger issue here is that your sanitizer demand is too high. If 5ppm chlorine disappears in 30 min means that there is something consuming the FC. This tells me that there are contaminants, perhaps even biofilms, in your spa, filters, or the N2 cartridge itself, that quickly consume your sanitizer. Without sunlight, ozone or lots of aeration from jets, 5ppm FC should decay down to no less than 3-4 ppm in 24 hours.
I would suggest you need to get the FC demand under control first, with a good purge/decon.
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yea good points. ... I should have qualified that I use predominantly bleach as my oxidizer. without the Borates I would seriously have to flirt with 30ppm TA to keep pH within reason ,when there was lots of agitation from the jets and of course the ozone generator. in the end it was just too stressful to consider the possibility of precipitous drop in pH due low TA, so I added the Boric acid on my most recent fill.
I might dry straight dichlor on my next fill just to experiment again with pH control and the drain interval.
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Here is my "no puck no floater" bromine plan with ozone and borates for hot tubs. This plan is essentially the “dichlor then switch to bleach” method except that sodium bromide salts are in the water. Here is why I like it:
- my family likes Bromine better than Chlorine; we have no allergies or sensitivities.
- I have no interest in expensive alternative sanitizer methods. Bromine is cheap – especially if one uses bleach for the bromide conversion
- Ozone assists in contaminant oxidation and also in the bromine conversion itself, which means no floater is required even when leaving the spa unattended for long periods of time.
- pH control is a breeze
Optional prep work: use the pool calculator to determine the amounts needed:
- Set aside the amount of dichlor that will produce ~35-40 ppm FC in the spa, i.e. about 1/2 cup for 500 gallons. This is my oxidizer until it is used up, at which time I have roughly 30-36ppm CYA, signaling it is time to switch to bleach. I note that with Sodium Bromide salts present in the water, I could skip the dichlor step and go straight to bleach, but this is extra insurance.
- (Optional – if you are using borates to help buffer pH). Set aside the amount of Boric Acid that will produce approximately 50ppm (-0/+10) borates in the spa (for a 500 gallon spa, 3 cups of Boric Acid calculates to 58ppm borates). Yes, I'm a borates fan
- Set aside the amount of sodium bromide that will produce 30ppm in the spa, i.e 2.5 ounces for 500 gallons
Initial fill:
1. I fill with straight tap water (with an outboard sediment filter attached to the garden hose), as my city water supply is very close to target balance numbers. Softened water or a combination of tap water and softened water can be used to achieve a lower CA level.
A note on heating: depending on the source water condition, the heater can be turned on as soon as the fill is complete enough, although I prefer to achieve water balance close to targets first.
2. Adjust CA level to target (120-150ppm) if needed. 130ppm is working well for me. If you must live with a significantly higher CA level, use the pool calculator to study the likelihood of a large positive CSI (in the event of pH swing), and consider using a scale control product regularly, per label directions. I like to use one for additional insurance.
3. Adjust TA to target, using Baking soda to raise TA (not likely you will need this) and the “acid+aeration” method to lower TA (run the jets to raise pH, then lower both pH and TA with dry acid). I target 50ppm TA with pH 7.6-7.8. Choose a target TA value that affords the best pH control over time, which you will learn from experimentation.
Water balance note: The method of controlling pH with a relatively low TA will require a higher CA to maintain a zero CSI. Nitro has reported good success with CA=200, TA=60, pH=7.8, which is dead on CSI=0 at 103 degrees (F) water temperature. Chem Geek tends to recommend a lower CA level, and reminds us that the CSI can be well below 0 for acrylic spas. My owner’s manual specifies a minimum of 50ppm Calcium to maintain warranty protection.
4. Add the Boric acid set aside earlier.
Note: Chem geek reminds us that Borates will soften the rate of an upward pH swing more so than a downward swing.
5. Turn on the heater if not done previously
6. Dose to ~10ppm FC (using dichlor).
Note on initial shock: This is a good opportunity to check FC decay rate (Note that sunlight, ozone, and agitation will cause FC to decay). YMMV, but I have learned that if I properly purge the OLD water first (dose with Ahh-Some and 10-20ppm FC before draining), and then immediately fill with my chlorinated tap water, that a high initial FC initial dose is unnecessary and I can start with a lower level, closer to 4ppm.
7. When the FC level drops to ~4ppm FC, I add 30-40 ppm Sodium Bromide from the quantity set aside earlier. This creates the bromide bank and converts the 4ppm FC to 9ppm Bromine. Dosing higher than 30-40 ppm sodium bromide is not necessary, but gives you insurance against bromide consumption or loss via splash-out. Dosing lower than 30ppm may result in a less than 100% bromine spa.
Note on adding Bromide salts: be sure to wait until FC has decayed to acceptable levels before adding sodium bromide, as your bromine decay rate (with ozone in use) will be even lower than with Chlorine. This is because, while ozone destroys free chlorine it actually helps convert bromide salts into bromine. With a clean spa and no sanitizer demand it can take days to drop the bromine level down to acceptable levels.
8. Enter the spa when temperature, water balance, and sanitizer targets are achieved.
Maintenance:
- A strong, Corona Discharge Ozone generator should be able to maintain a non-zero Bromine level under ideal, no-load conditions in a 500 gallon spa. In my Hot Spring Grandee, I typically see levels ranging from “Just a hint of pink” in the FAS-DPD test, to 1.5 ppm.
- I test regularly using the Taylor FAS DPD test for Bromine kit (2106).
- I use MPS from time to time as my oxidizer, as its Bromine conversion rate is a little slower than Chlorine, and so it will behave as a native oxidizer for a bit longer.
- Although this isn’t as important in a bromine spa, I start with dichlor as my oxidizer until achieving 40ppm CYA, and then I switch to bleach. Sometimes I switch to bleach early for the fun of it.
- I purge with “Ahh-some” on every drain, and every time, the results confirm that it is beneficial to purge every time
- I mix “Ahh-Some” in with a traditional filter degreaser to clean my filters.
- To accommodate Bromide bank depletion I add an once or so of sodium bromide over life of the water just to be sure
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I took some photos of 6-month old well-maintained perfectly crystal clear water compared with a fresh fill, and can corroborate the above. Water can be crystal clear but still not sparkle, and you can detect this without any agitation or bubbles, although I fully agree with your comments re: nature of the bubbles.
I can't emphasize enought that there are benefits from purging with Ahh-some every drain, which I am doing now with very few exceptions. It takes so little extra time to add a few dollars worth of Ahh-some to the water before you drain, and the reward is, well you just don't know until you see what you think isn't hiding in your pipes.
If you start out with a clean spa, manage balance, CYA, and don't let the sanitizer level drop to zero, then you won't be concerned about TDS as a measurement, and you will drain the water because it doesn't sparkle any more, even though its crystal clear.
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Verdict on 50ppm Borates in a bromine spa; I like it. I found that pH rise is so much easier to control, so I switched back to Boric Acid method -- 3 cups per 500 gallons.
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I did extensive testing and went through thousands of gallons of water, testing several different products. by far my strongest recommendation is Ahh-Some. I have written up a detailed experimental description in pdf form, but haven't posted it anywhere. Here's the bottom line:
Natural Chemistry "Spa purge". overloaded with surfactants that produce epic amounts of foam, but does very little
SeaKlear "system Flush". does very little
Silk Balance "Clean Start". just borax in a really expensive container. does nothing. If you want borax, go to the grocery store
Aquafinesse "spa Clean". completely worthless
Unique Solutions "ahh-Some" woh baby. be prepared to learn what is lurking in your pipes and the pleats of your filters!
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If you are using only the N2 silver method with no suplimental sanitizer (chlorine) or MPS shock, your water contaminants can get out of control expecially with a high bather load. A new tub with those kinds of issues -- if it were me I would start over.
keep in mind the context I am assuming here is a portable spa, which I am familiar with.
I would purge with Unique Solutions "Ahh-Some" (follow the directions there). If this treatment releases a lot of material, refilll and dose again with Ahh-some. (Note--my new spa requried a two-purge treatement because it came delivered with biofilms already growing). clean your filters with a mixture of traditional degreaser and Ahh-Some. Straight degreaser alone is not enough to clean the filters -- based on my experiments. Without knowing the details of how your spa has been used, and the sanitizer treatments you have used, I would lean towards an agreesive approach that includes a chlorine decon (on the final Ahh-some purge), to insure a kill of whatever ahh-some releases.
there are many variations on this basic theme, and I might be jumping to conclusions here, but I suspect you might not have shocked with MPS often enough, or supplimented the N2 with chlorine to keep up with a high bather load.
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just an additional comment -- before i started using borates as a pH buffer, I found it was not uncommon for pH to spike up to 8.0 or even higher -- due to lots of water agitation, ozone, and when using bleach -- even with TA down at 35-40ppm. I found that a little insurance doesn't hurt, so I would treat with a stain and scale control product (I used BioGuard stain and scale control).
YOu can use the pool calculator to see, based on your CA, how close you might be to preciptating calcium in the event of an unwanted upward spike in pH, and you can decide if you might want to mitigate the risk chemically. Since experimenting in this area, I've taken to using borates and find the pH control to be wonderful, and especially beneficial under these circumstances .
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+1 on the CYA build up. To avoid this, I calculate the amount of di-chlor that represents 30-40 ppm CYA in my spa. that is a fixed amount that can be mesaured. I set this aside , and use this first. When this is used up, I switch to bleach.
Another point to make ... as we're talking about neat and clean water -- is my own learnings regarding the importance of a good purge. According to my own experiments, I'm convinced that my spa came delivered with biofilms already present and growing. I had troubles with sanitizer demand even on the first fill, and didn't get things settled down until purging with "Ahh-Some". I've written about this previously, but basically nothing else (that I tested) comes close to the effectiveness of this stuff -- I now purge every fill or sometimes every other fill.
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Hot Spring highlife is their top of the line -- I just replaced my 25 year old Grandee with another Grandee because I like em so much.. and ditto on the dual moto massage jets. they really are twice as good as the old single ones. I'm also not a fan of lounges. We have kiddos in ours all the time and when they get hot they just sit on the side -- the Hot Springs (and many others) have sides that are strong enough to sit on. you just don't want anything hard/sharp (like a pocket zipper) to come in contact with the acrylic.
The Hot Springs mfg is top notch; while I can't comment on the other product lines directly but I suspect the main difference is in features and plumbing complexity -- such as integrated ozone, compatibility with their ACE system, lighting, sound systems etc. As for the plumbing itself, I think the used Hot Springs are a good used investment, as they are filled with foam insulation which mitigates the kind of shock/vibration the equpment would otherwise endure. Beyond the obvious (make sure everything works, touch all controls, validate all features, etc), the main areas I would encourage you to inspect are:
1. look at the bottom of the spa (tip it up if possible), and look for evidence that the frame might have sat in water. if a dealer is selling the spa, they should be happy to show off the botrrom of the spa. the foam should be bright and without evidence of any leaks, and the wood should be dry with no evidence of mold or structural compromize. Spas that sit on concrete pads can still collect water around their edges. On my newest Grandee I poured a special 3" high pad (on top of my concrete patio) that matched the exact form/shape of the spa under frame. So the spa sits up in the air 3 inches higher than normal. I did this for strength, but also, because there is no chance for water to accumulate against the wood frame -- all water spashes down and runs along the concrete and not along the wood frame.
While you're looking at the bottom of the spa, find a way to put a straight edge along the critical frame pieces to see of there is any warpage. A spa filled with thousands of pounds of water will eventually conform to the concreate structure upon which it is resting.
2. inspect the equpment compartment. look for coorision around the heater connections and general cleanliness, no water, etc. in there. look at all the visible wires, pipes and such, and make sure you see no evidence of leaking
3. inspect the acrylic surface when it is dry. a used spa is bound to have a scratch or two, but you want to make sure there are no cracks or large imperfections. especially if the spa is at a dealer, you should be able to climb in and look at every square inch
4. check out the condition of the filters - you may need to replace them, which is not a bad idea. I'm especially fond of the ceramic ones -- so durrable and practical.
And this next piece of advice is probably the most important of all -- before you use any spa, especially a used one. PURGE the vessel, regardless of what the previous owner or the dealer tells you they have or have not done, . I've done a boatload of experiments on my own spa -- and I purge on EVERY DRAIN (unless weather gets in the way). I can recommend only one product for this purpose -- Unique Solutions "Ahh-Some". its not that expensive but holy toledo you won't believe what that stuff will release from your spa. I've tested several others, and remain astonished at what they don't do, but this stuff works.
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nice comments Chem Geek. yea I've done the Borate thing and found it to be effective, and now on my current fill I'm trying the 'without borates" method. Since pH rise is such a problem in hot, agitated water, I also have taken to adding a stain and scale control product for additional insurance, and recommend the same to others, although on this fill I have not done so , for experimental purposes. I will probably go back to using Borates.
scaling: I have a similarly amusing anecdote. the colleague with whom I am working now came to me because he is taking over spa maintenance from his wife, who once added baking soda to their tub and found that white scale mysteriously appeared. the spa store told her it was a bad batch of baking soda and to always use properly labeled TA increaser! I about died laughing. I encouraged him to study different numbers in the pool calculator, as when you do that, you can very nicely model different scenarios and how vulnerable you are to scaling. I showed him he was probably running close to "the hairy edge) re: water balance and the added soda caused his water to scale. now he understands. whats even more funny is that his wife was saying "why does this have to be so complicated?" and "I didn't have to worry about this many parameters", when he politely retorted, "yes but you also put calcium all over the walls!" lol
I can validate that when using bleach in my bromine spa, that pH rise is more of an issue than when I use dichlor. I see your point about pH control and Borates being more important in a Cl spa. I find that pH control is acceptable, but I'll use Borates next time just to see the difference.
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nice work. glad you posted again, as I lost track of this thread and frankly I didn't make it over to TFP as there was not much spa activity over there. I am really liking the bromine+ozone method in my tub. no floater, and the OG keeps Br levels high enough, under no load conditions.. yea, your CA may be higher than necessary but its not too high, considering the TA=50.
I have to tell a funny story -- after consulting with a colleague at some length, to lift him out of the "spa-store fog", I finally got him to see that a low TA was necessary for pH control under heated/agitated water conditions. later he contacted me ,saying he followed the Spa store's advice to target TA of 120ppm, and why did my pH just shoot through the roof? then he realized that he would be using dry acid to control pH, and that TA of 50ppm ish would be needed for that :-)
On that note -- and from my personal experience; I have seen TA drop down below 50ppm in my spa, but what I've learned is that TA is something to monitor, not to target by itself. what I mean by that is the real measure of success is pH control, not the TA number, and since the vessel is tiny (compared to a pool) and because people and spa utilizations differ, one size doesn't necessarily fit all. . So even though TA=50 "ish" is pretty much required to achieve good pH control in a spa, I don't place any magic on the number anymore. 50ppm is, in fact, a little high for me to avoid pH upward drift. 40 is more like it. I simply control pH drift with dry acid, as the utilization/agitation of my water demands, and I watch TA to make sure it doesn't go too low because I know that when that happens there is danger of a precipitous drop in pH. When pH drifts high under lots of agitation, and TA is low, it takes very little acid to bring it under control again.
best of luck on your spa; sounds like you have it well under control again. BTW ahh-some is way cool. its the only purge product I have confidence in.
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ok good plan. keep purging until your Ahh-some dosed water produces no new material. If you get just a small amount of gunk, you don't have to drain -- you can wipe it up with a cloth -- then rinse the cloth in a separate solution of Ahh-some. this will take several wipe-rinse-wait cycles. If this is not successful than drain and re-dose. The goal is to have Ahh-Some dosed water that does nothing except make the water cloudy and produce white foam that does not stick to the sides. . I find that the label directions are pretty aggressive as regards to the ahh-some dose. After your first 2 purges I bet you could reduce the dose (like I did) to about 75% of the prescribed amount.
it may not be worth it to repair the OG -- I would look into replacing it with a modern corona discharge type, which are more powerful than the older UV types.
I just don't see the need for 320ppm calcium unless you are trying to control foam. If there is Calcium build-up on the spa walls, that means there is calcium on the heating elements too. you may need to replace those... but if they fail you will know it :-).
To left justify the text, you have to put this tag at the beginning of your text:[left]
and put this tag at the end of your text[/left]
Note that if you edit your post, the system will strip out these tags and you have to enter them again. I'm about ready to switch to the TFP forum on account of that -
there are a few things that are not right.
I indicated that 10ppm Bromine was oversanitizing. but you removed the bromine floater when you had a PROPER level of bromine. now you have only 1 ppm bromine which is very low. if you used the tub while bromine level was 1ppm, with the floater still removed, then probably your bromine level went down to zero under bather load. that can cause disease to grow in your tub.
320ppm CA with your 60ppm TA and 97 degree temp shouldn't cause any problem with the water balance. Why did you raise your calcium? that could make people's skin feel itchy.
if people are coughing with the jets on then something is wrong. A 16 year old used tub is growing bad things in it, for petes' sake. you need to flush with Ahh-some and superchlorinate before people get sick. why are you wondering if there is another method? A contaminated spa will spread bacterial infections via the mist that people breathe. if you are perceiving a strong chemical odor with low Bromine levels then your test is either not accurate or something is wrong. I say quit messing around with this tub -- it could be dangerous. forget the "run a couple of cycles first" thing -- Do the Ahh-some purge now.
A device that you plug in and that " bubbles air into the tub on a tiny port", is likely an ozone generator. If it too is 16 years old then it probably has a UV bulb in it that is worn out or not working at all. You can smell the sweet smell of ozone. if you don't smell it, it probably isn't working, but you should not assume that -- get it checked out. UV bulbs are expensive... you'll have to decide if the cost is worth it. -
Ahh-some is about $6 per 500 gallon purge,
So the data show that a very small amount accumulated in controlled conditions that don't correlate very well with residential spas and hot tubs. That appears to offer a non-zero attenuation to the belief that biofilms will never form under conditions that happen in spas all the time (very small but non-zero FC). It is disappointing that the summary really wasn't truthful, however. I suspect that if a study set out to prove that biofilms could not accumulate under the conditions of interest, it could be faulted as well because that is a very difficult hypothesis to prove. -
interesting. yes I did catch that, although they stated "biofilm was able to accumulate" they also stated that this result was accompanied with a 4 log reduction.
I suspect that marginally favorable conditions (for biofilm growth) may exist in the residential spa more than most are willing to admit. consider that sanitizer levels could drop to near (but not) zero (or even zero for a short time), perhaps even in localized points in the pipes, and that zero flow rates in the pipes, especially at the boundaries where biofilms normally form, will occur. So it seems plausible to me that bad guys could find a way to take hold. But I do agree that -- in a (starting) condition where there is truly zero accumulation, no infection, and proper sanitizer levels., the evidence is compelling that biofilm formation is unlikely. But I also suggest that these conditions rarely, if ever, happen. A Spa, is really never sterile to begin with. Even with an Ahh-Some flush, I suspect we would be hard pressed to claim that fully 100% of all contaminants and nutrients supporting biofilm growth, or 100% of all biofilms, are removed. I'm convinced that Ahh-Some is the closest we have to this, but suggest it would be silly to claim a 100% sterilization. With that in mind, the more nefarious mechanism could very well be regeneration or biofilm recovery and regrowth. For example, Paula Dreeszen** states that "incomplete removal of the biofilm will allow it to quickly return to its equilibrium state, causing a rebound in total plate counts following sanitation". Of course this has to do with chlorine treatments in drinking water supplies, but this statement reminds us that a spa flush could create an environment where the rebound could occur, especially if the marginally favorable conditions mentioned above (including slime that has not been completely removed) are in place at some time. Dreeszen also cites Characklis (1990) who suggests that biofilm recovery after chlorine shock is faster than initial accumulation on a clean pipe, and that surviving organisms "rapidly create more slime as a protective response to irritation by chlorine".
So -- it seems to me that all this just strengthens the evidence in favor of regular purges with the most effective method/product one can obtain. In my situation, Ahh-Some released a lot of stuff which had formed over the previous 6 months. This stuff may have been dominated by oils, greases, etc, which I will readily acknowledge, but it seems equally prudent to avoid stating that there could have been no biofilm material present at all.
"Biofilm. The key to understanding and controlling bacterial growth in automated drinking water systems", second Edition (June 2003)
Hotel Hot Tub With Excessive Foaming
in Hot Tub Water Chemistry
Posted
just a quick observation from my own experience - Hotel spas are expecially vulnerable to foaming because guests often don't shower and their bathing suits probably have soap residue -- the problem is just tougher to deal with in a public setting.
not to interrupt the fine advice from Chem Geek -- but Calcium hardness is easily raised with the addition of dry Calcium Chloride such as in the below example.
http://www.intheswim.com/p/calcium-hardness-increaser
FYI I have personal direct experience with Ahh-Some myself, having completed a rather comprehensive set of controlled experiments. nothing else I know of is capable of removing what this stuff can remove; I highly recommend it