Spa Purge Product Shootout -- 2Nd Experiment

[dlleno]

Back in February of 2014 I presented test results of two purge products, SeaKlear System Flush and Unique Solutions Ahh-Some. The motivation for this experiment was (1) to cure a known-bad water problem, of which I presumed (and later verified) to be caused by biofilms shipped in my new spa, and to (2) compare these two products effectiveness. This original thread is found here:

http://www.poolspaforum.com/forum/index.php?showtopic=45727

The important result of this experiment is that SeaKlear did in fact produce a visual result, at least when applied to my bad water, but that Ahh-Some was able to pull a great deal more material from the spa itself that the SeaKlear did not touch.

The purpose of the present post is to summarize a new experiment which I recently completed, during which I compared three other products to Ahh-Some. Given that my working hypothesis would remain the same, (namely that Ahh-some releases material that others do not), my experimental method remained the same as well I would test with the competing product first, and then follow with Ahh-Some. If Ahh-Some released more material after another product had done its work I would declare the hypothesis valid. If Ahh-Some did not produce any more material than the others, I would declare the hypothesis invalid and the Ahh-some claims to be false.

The present experiment, however, was conducted under different conditions. This time, in addition to testing products, I would be able answer this question:

Can biofilms form even under ideal maintenance conditions with crystal clear water and no unusual sanitizer demand?

To conduct this experiment required many hours, thousands of gallons of water, patience and a lot of work, but it paid off with a clear result. I will not present all the details I have documented, as this would consume some 25 pages including photos. Instead I will summarize my test steps, the results obtained, and conclusions reached. Note that except for the first product tested (Clean Start), all purges were performed on new, fresh water fill, heated and balanced to the same parameters. The products were tested in the order listed. I will describe the experiments themselves in a reply to this post

Edited in attempt to override the annoying center justification

[dlleno]

Silk Balance Clean Start. One normally does not think of this as a biofilm removal product, but the local dealer touted that it would be good for that. I removed my filters, placing them into a solution of traditional filter cleaner and added the prescribed amount (56 oz) of Clean Start to my 6-month old well-maintained water. This product is nothing more than Borax in an expensive container. It accomplished absolutely nothing except to produce a little foam and drive my pH through moon, but It released no contaminants. Not even a spec. I consider this one a placebo. I do like the container though it helps me scoop out water from the molded seats when I drain.

Aquafinesse Spa Clean. Same result: absolutely nothing released. A complete waste of 1000 gallons of water. Another placebo.

Natural Chemistry Spa Purge. This product released a very tiny amount of contaminants an amount hardly worth noting, in fact. What Spa Purge does is create foam -- truly epic amounts of foam. I had to shut the jets off to avoid treating my lawn with this stuff. But it really didnt do much of anything useful. I was left with the impression that specific foam producing agents have been added to this product, just for the effect.

Ahh-Some. After three successive but unsuccessful attempts to clean my pipes with the above products, I refilled yet again and put in the prescribed amount of Ahh-Some. Woh. I got all kinds of white and off-white sticky gunk on the sides of my spa. The absence of brown gunk puzzled me, and I began to wonder if the previous three products might have contributed to or influenced the result I was now seeing. Unsure if the single Ahh-Some purge was completely successful I drained and filled again, and treated again with Ahh-Some. This time I got a boat load of brown stuff more along the lines of what I was expecting originally.

Unsure if the 2nd Ahh-Some purge was successful I drained and filled again, and treated for a THIRD time with Ahh-Some. I got nothing. yippie!

Conclusions:
1. Biofilms DO form even when you start out with a clean spa and when your water has been well maintained. Prior to this experiment I had purged with Ahh-Some, and 6 months later my water was still clear and there was no unusual sanitizer demand.

2. Ahh-Some is, by leaps and bounds, superior to the other products I have tested. For the purpose of removing biofilms, the other products I tested just do not perform and are useless for the intended purpose, in my opinion.

3. Chlorine shock cannot be depended on to remove biofilms. Note that prior to purging with Ahh-Some the first time, I shocked to 50 ppm Chlorine, and I still released copious amounts of biofilm. Im not saying the practice is fruitless or that it wont provide some attenuation. Im saying it wont remove biofilms outright especially those that are chlorine resistant.

I acknowledge that not many have purged their spa with new/clean water. Thus, I suspect that the above products, particularly Natural Chemistry, would surely produce some effect (even an impressive one) under the conditions where most people would purge when there is a known problem.

Encore: So you think your filters are clean? Think again. I had a squeaky clean spa, dosed with Ahh-Some, just sitting there and I couldnt resist the opportunity to see how clean my filters were. So I installed them into their normal positions and held my breath: instantly I saw new brown deposits accumulating on my walls again! This time the amount of material was small, and I was able to wipe it up with a soft cloth which I rinsed in a separate solution of ahh-some. That process took about 30 min.

Conclusions;

1. Biofilms can form in your filters even when both they and your water are impeccably maintained. Ordinary Filter cleaner/degreaser is not sufficient to clean the biofilms from your filters

2. One again, Ahh-Some rules. From now on I will be cleaning my filters with a solution of Ahh-some plus some degreaser to be decided later. I might even use Ahh-Somes own filter cleaner, which I suspect is a similar recipe.

Edited in an attempt to override the default center justification of text

[chem geek]

Great experimentation! My only comment is that after the initial Ahh-Some and then 6 months of use, what Ahh-Some then removed when it was used would not necessarily be biofilm since it also removes greases and oils and other material that can accumulate on surfaces. You'd have to do analysis of the gunk that was removed to see if it was greases/oils or if it's biofilms (or both). Usually with biofilms the chlorine demand will go up but that depends on the quantity and their growth rate.

Chlorine doesn't oxidize all chemicals nor does it oxidize chemicals completely except for some of them (ammonia, for example).

By the way, how do you remove the annoying centering justification?

[dlleno]

yes, true enough. especially the first release -- all that white stuff: its impossible to know what that stuff really was; whether the other products contributed to, or influence its appearance or not, I will never know. What does white water mold look like? Anyway, the important part was ahh-some removed it.

I agree that one can never be certain without direct test evidence that any given material is biofilm. But given that biofilms can be chlorine resistant, and given the plethora of information available, I think we can reasonably conclude that it is just as fallacious to assume that no biofilms were released in the experiment, or that biofilms cannot be present without an unusual chlorine demand. The reason I suspected that biofilms were released wasn't well described in my post, but there were three major ones:

1. The appearance of the material in the 2nd Ahh-some purge (the brown stuff) was remarkably similar to that removed by Ahh-some last winter (following the SeaKlear purge), when I was attempting to correct a known problem with the new spa. no doubt oils and other "non biofilms" were part of both experiments.

2. Having used three other products to purge the spa, the evidence favors material that the others didn't touch. I would expect the other products to have purged oils and greases and lotions and what not, but the data show that these products released none.

3. After having treated my filters with a traditional degreaser, the ahh-some still released material from the media, and one can reasonably conjecture that it was biofilm because all the oils and other material would have been removed by the degreaser, at least in large part.


oh-- yes thanks to waterbear: the annoying

center justification

can be remedied by enclosing your text in the BB code "left" enclosed in brackets. be sure to pair this code with a corresponding "/left", also enclosed in brackets! Also note that when you edit, the system likes to strip BB codes and they end up disappearing.

now if we could just eliminate the annoying "mysterious dark screen" and the add popup. I'm about ready to leave this forum on account of that. is TFP any better?

[chem geek]

None of the other forums have this center justification nor pop-ups.

As for biofilms vs. greases/oils, that's still not definitive because Ahh-Some has powerful surfactants stronger than in most degreaser products. If you didn't experience a high chlorine demand, then it's less likely to have biofilms especially in the filter because that usually leads to higher chlorine demand at least if the biofilm material is growing. The reason is that biofilms contain a mixture of polysaccharides that chlorine doesn't react with along with proteins that chlorine does react with (at least some of them). It is this reaction with the proteins in biofilm that slow down chlorine's penetration into the interior -- otherwise, it would enter the biofilm to kill the bacteria since hypochlorous acid "looks like" water. If there wasn't enough material to mire down chlorine, then it would kill the bacteria in biofilms, but usually with active biofilm such materials are continually replenished/reproduced so that the outer matrix is maintained and that creates a fairly continual chlorine demand that is measurable if the biofilm is large enough.

This paper showed that chlorine alone DOES largely prevent biofilm formation though it does not remove existing biofilms. This was a simulated high bather-load environment equivalent to 1 bather per 350 gallons per day adding chemical components of sweat and urine along with bacterial inoculum simulating fecal matter. Chlorine was used at 1-3 ppm FC though with no CYA and compared to the untreated control this resulted in a 5.33-log reduction in bacteria on plaster coupons from 1.26 million CFU/cm2 to only 3.7 CFU/cm2 which is negligible (that's 4 bacteria or very small groups of bacteria per square centimeter -- not biofilm colonies, but individual bacteria). In the sand filter (which is more prone to biofilm formation than a cartridge filter), there was a 6.70 reduction from 1.10 billion CFU/g to 219 CFU/g. This is more substantial though again is more common in sand filters. The paper also showed that super-chlorination with chlorine to 10 ppm FC for 16 hours weekly (again with no CYA) reduced bacterial counts on plaster coupons to 1 CFU/cm2 which was the detection limit and for the sand filter to 1.25 CFU/g.

The equivalent FC with no CYA for 4 ppm FC with 40 ppm CYA at 95ºF would be 0.3 ppm FC with no CYA at that same temperature so lower than the aforementioned experiment, but the point is that I think it much, much more likely for the large accumulation of bather oils, dead skin cells, and other material including that partially oxidized by chlorine to be the "muck" that Ahh-Some very effectively removes. That's still a good thing, of course, but it's not the same thing as biofilm. Biofilm is very real and in new wet-tested tubs where water has been retained in the pipes it can be a serious problem.

Nevertheless, I have no problem recommending using Ahh-Some on every water change if that is what someone wants to do. It certainly doesn't hurt and it does remove an accumulation of stuff, whatever that stuff may be.

[dlleno]

yes I have no issue acknowledging the uncertainty, and in fact the evidence you point out, suggesting the likelihood of oils and grease, as part of if not dominating the volume of material released in my experiments. But we should also point out that the uncertainty goes both ways, and while the abstract of the paper you cited is quite clear that chlorine did provide measurable attenuation, one cannot conclude that proper sanitation will in fact prevent all biofilm growth:

"Results showed that the biofilm was able to accumulate on coupons and in the filter systems of reactors treated with either 13 mg/L free chlorine or 10 mg/L polyhexamethylene biguanide (PHMB).

[chem geek]

Yeah the paper has info in the abstract and conclusions that quite frankly are inconsistent with their reported results -- you have to pay for the paper to read it thoroughly.

There is no way one could consider 3.7 CFU/cm2 on the plaster coupons to be biofilm (and remember that their limit of detection was 1 CFU/cm2). That's just ridiculous. Four bacteria (or a small mass of cells) over one square centimeter is NOT biofilm. That's just bacteria from their three times a day five days a week inoculation/addition at the rate of 5x10^7 (that's 50 million) viable cells per day some of which survived from the chlorine long enough to got nestled in the plaster coupon to be barely alive when they swabbed it and made a culture (they did not say how long they waited between their last inoculation and their bacterial count measurements). It was like this for one month with two of the three plaster coupons placed in "dead space" with little circulation (though still in the water tank). Samples were taken on day 14 and day 30. The untreated control got so out of control that the system failed after 2 weeks (excessive plugging of the tubing) so samples were measured only on day 14 in that case.

In practice in residential spas properly maintained by chlorine, where you find biofilm is above the water line. You can usually tell because it can feel slimy, but can be dealt with by regular wiping of the surface.

[dlleno]

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)

[chem geek]

Again you need to buy and read the paper since their statements "Results showed that the biofilm was able to accumulate on coupons and in the filter systems of reactors" and "All the treatments tested resulted in at least a 4 log reduction in biofilm density when compared to the control" are extraordinarily deceptive if not downright false in part. First of all, the 4-5 log reductions were with PHMB, but chlorine showed 5-7 log reductions. Second, when a log reduction is so high and when not measured over minutes but over weeks then it is not particularly relevant. What is more relevant is the actual ABSOLUTE amount of viable bacteria left in spite of regular three times a day addition for a month (along with plenty of bather waste nutrients). That's where 1-3 ppm FC chlorine without regular superchlorination showed a 0.57-log10 (cfu/cm2) accumulation which is where I converted this to 10^(0.57) = 3.7 bacteria or clusters (colony forming units) per square centimeter. Superchlorination was most relevant for the sand filters and not needed for the plaster coupons.

I'm not opposed to a regular purge when the water is changed. It's not that expensive when done that infrequently and it does remove at least the accumulation of skin oils and other material so if there are biofilms to remove then great but even not then also OK. I just don't want such justifications to be based on dubious science (well, summaries and discussion -- their actual reported data was fine). If you used sand filters in your spa, I'd say there was much more likelihood for biofilm in the filter, but residential spas usually use cartridge filters that tend to have fairly even flow and chlorine exposure. As for pipes, that's also a likely place for those pipes that are used infrequently -- say some jet pipes only used on occasion.

I've just monitored Dichlor-then-bleach reports on this and other forums ever since I proposed it years ago (some people did use bleach in the past, but not clear if they understood the need for some CYA initially -- most spa users use Dichlor-only) and the only problems were when chlorine wasn't maintained. And yes, it doesn't take long for a spa to go south if the chlorine gets near zero. Bacteria can double in population every 15-60 minutes under ideal conditions so one bacteria can become over 4 billion in just 8 hours (in practice their is a slow phase before more rapid growth so this is an extreme example). A real key test is chlorine demand and another is any reports of hot tub itch/rash/lung or other skin issues.

Also note that spas with ozonators may have less issues because more organic material is broken down and if there is any small residual of ozone that makes it to the circulating water then ozone is effective against biofilm.

If one wants insurance against biofilms in case their chlorine level isn't properly maintained, then use of the strong surfactant products can be used to supplement, but that gets more expensive.

[dlleno]

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.

[Susanj]

So to use Ahh-Some, I add it to the spa, drain, refill, drain again and refill?

[dlleno]

thats a good overview/summary yes.  There are some details that the label directions will outline, such as adding chlorine, removing the filters, ,etc.  But yes you have the gist of it

 

BTW I have re-written the account of my experiences with purging on a blog.  its just a more polished presentation (with photos)

 

http://boisediesel.com/blog/2016/7/spa-purge