Although I can't remember the source of this (I am pretty sure it was another conversation on the PGN forums, on another topic), I read that although pool enzymes can be beneficial in the short-term, as they themselves break down in a pool environment, they can actually add to the oxidative load.
Anyone remember anything like that? Anyway, I'm wondering if there's something to it. In my 18,000 gal "trouble pool" that I discussed under the breakpoint chlorination thread, we have been using enzymes for about a year with some success of at least keeping the combined chlorine below the WI max of 0.8 ppm.
As time goes on though, I'm noticing that the combined residuals have been climbing faster in between each time I use the enzymes. Although my bather loads in there are starting to climb to their typical summer numbers, I noticed the last few times my combined ppm can jump to 1.4 or worse in a day or 2. At around this same time last year, without using enzymes, and with similar bather loads, a usual "bad day" would be between 1.0 and 1.2.
As much as I wish I could add UV/Ozone tomorrow, it's not my decision to make. I think the enzymes have been a real help, and hope they will continue to be. If I see things get even worse, I will definitely post it here!
Let me try to add a few comments without confusing the matter further. While enzymes are considered proteins, the % of protein contained in our product is exceedingly low in the grand scheme of things meaning they don't add too much to the load nor add to the chloramine problem. Their benefit actually works in reverse by reducing the "oxidative load" as you put it.
Why I believe they can be beneficial with combined residuals I think they do so by catalyzing or helping break the organic bond between the ammonia & the free chlorine. I agree these results are not always consistent. One common denominator I've found which impacts these results is high phosphates. I suggest you check your phosphate levels in this trouble pool and make sure they are at or below 200ppb. I've had far more luck consistently reducing combined levels when I know phosphates are under control.
I also believe you need to use the right enzyme and be consistent with your application not being afraid to double the label application rate.
I agree with Tom's response. If you are finding that the use of enzymes is increasing either chlorine demand or Combined Chlorine (CC) levels, then you are using too much enzyme or using the wrong kind of enzymes. Enzymes are catalysts so a small amount goes a long way since they are not consumed in the chemical reactions that they accelerate. Enzymes will break down over time, but their quantity should be relatively small.
Agreed, with too much "demand" in the water for chlorine...phosphates and organic load..it makes it difficult to bring down chloramine levels and keep them down. Great topic!
Thanks both for your input. I follow the dosage instructions as listed on the bottle, so as long as the label isn't BS, I'm confident I'm not overdosing.
Likely in the interest of sales, the label does encourage doubling the dose, which I don't do! As of right now, I have no way of measuring phosphates, which I may fix shortly...
I should have mentioned that my chlorine demand has been relatively unaffected, and I'm not exactly sure of bather loads (Lately our lifeguards have been leaving a lot of sections blank - based on what I've seen throughout the days though, we've been within the same historical ballpark).
As for picking the right enzyme product, is there an objective way to do so? Trolling websites I've seen multiple manufacturers make almost word-for-word identical claims of grandeur, without differentiating themselves from another by describing in detail their contents or manufacturing processes. I get that they don't want to disclose proprietary information, but if their product was so effective, wouldn't they be able to survive the scrutiny of the patent application process and have the protection they'd need to profit off their R&D?
Until I have some assurance that that or some similar independent verification has been done (and see the data to go with it), how can I trust the claims of company X vs. company Y?
Once again, thank you both. I will see what I can do about testing phosphate levels, and I will also try scaling back the enzyme application frequency (the bottle says to go weekly or more, and I have been averaging weekly use. I will try skipping every other week and see if things get better or worse).
I will let you know what happens!
Good morning, Thanks for the input. I want to be careful not to turn this into a selling forum, but enzymes aren't all created equal. I happen to be the Product Manager for Great Lakes Bio Systems and we focus on supplying industrial grade enzymes for commercial applications. If you would send me an email to email@example.com we can discuss this further outside of this forum that would be great...ok enough selling.
Admittedly there is little hard data that suggests that with every dose of enzymes chloramines will be reduced 25% for example. Enzymes are not the end all be all solution. They are simply another effective tool to have in the tool box. There are several parameters that also impact these results, but one that does frustrate me is most facilities managers at the various YMCA's, high school & municipal pools etc. where are enzymes are in regular use aren't able to track chloramine levels consistently and I have very little historical data to compare it to.
They love what a commercial grade enzyme does to their water quality, yet when I ask them about chloramines they say "yes we did see an improvement" but nothing to back it up. So, I have absolutely no problem with your assessment there's a lack of data.
In general terms what I would suggest is enzymes are most effective when injected at a greater frequency. I'm not necessarily talking about greater volume I'm simply saying greater frequency of smaller doses. So no matter what enzyme you use and refer to in your notes I would have you go the other direction and add more than once a week.
Here's the primary reason...your bather load may or may not be consistent but you do have organic material being introduced by bathers every day. Unfortunately the same can be said for phosphates as there are plenty of sources that contribute to this. So more frequent dosing of enzymes simply helps you keep up with the constant fluctuation of organic material.
Your comment about chlorine demand may also be telling and indicate phosphates are at a reasonable level already. Hope this helps.
Ideally, the enzyme product would be able to accelerate the oxidation of urea and its chlorourea derivatives. Urea is the largest nitrogenous component in sweat and urine and is very slow to oxidize with chlorine alone. The chlorourea likely shows up in CC tests and its further oxidation by chlorine leads to copious amounts of nitrogen trichloride (see this paper).
You guys are great, thanks!
Tom, I will get in touch with you by next week at the latest. Richard, I remember your detailed posts both replying to mine in the breakpoint chlorination thread, as well as some of your more detailed posts breaking everything down in some of the other pool chemistry threads.
Hopefully I can either get our enzyme application to be more ideal, or I'll try a different product. We do our combined chlorine tests daily, and sometime twice daily, and I can say that 90% of the time, and enzyme application gets our combined chlorine from 0.8 to 0.6 within 24 hours. Sometimes we'll have 1.2 to begin, and the enzyme can get us back to 0.6 or 0.8. So as far as making claims goes, I think the claims are founded, I just wasn't sure if there was any kind of breakdown that was in the end adding to the oxidative demand. Thank you both for helping clear that up!
Al just emailed me, and if we can make our schedules work he's going to drop by and see/smell our lovely pools!
Once again, thank you both!
Had I sent this reply before reading yours I would say the range of reduction would be 25% to 50% conservatively and sounds like what you're experiencing. Enzyme activity is relatively rapid so again an over night reaction seems in line.
Enzymes (at least the ones we ferment) are inert and don't require a grow out time, thus their reactivity is quick, or relatively so in terms of what the pool industry is accustom to experiencing.
In comparison to all the crud your swimmers leave behind (some studies suggest 32 ounces of bodily fluids per person for each hour in the water) I can't think that whatever oxidative load is added back into the water as a result of the enzyme breaking apart the combined chlorine has any net effect.
In industrial applications the best pH range for the conversion of ammonia to nitrite (NO2) is 7.8 to 8.0 and a little lower to complete the nitrifying process fron nitrites to nitrates...something in the range of 7.3 to 7.5. The specific types of bacteria that work in these ranges are not found in pools of course. Some that may are various bacillus species that are also capable of this denitrifying process.
All of these bacteria rely on their own enzyme production to provide the necessary catalyst to start the ball rolling on cleaving these various complex carbon chains. This is why I feel we do see an improvement in chloramines with regular and consistent applications of enzymes. An improvement mind you not total elimination.
Just in the interests of keeping everyone up-to-date, Al was here a few weeks ago & saw just how unappealing the pool looks, and he did reveal that we have a phosphate problem (over 3ppm). He, myself, and Tom discussed an action plan, and this should give us both an opportunity for improvement, as well as a chance to get some more real-world results.
In the short-term, we're going to double the dosage, as the product we're using is marketed as a consumer product and is roughly half the strength of the pro product. We're also going to break it up into a daily dosage level to see if we can more steadily maintain both the amount of enzyme and the CC.
This will give us a good set of baseline results that show how effective the product is with high levels of phosphates present.
Given that our source water (according to the utility, we'll find out for sure once I get a phosphate test kit in July) has no phosphates present, that would indicate that our phosphate problem is most likely coming from our sequestering agent, which according to the MSDS is: 2-phosphono - 1,2,4-butanetricarboxylic acid. In the long term, I am looking at different products.
Once we drain & start the pools back up in August, I will test for and correct any phosphates present.
I will probably immediately begin use of the enzymes on the same dosage & frequency as before, and we'll see what difference we get. The only thing that will throw off our results will be the fact that bather loads will be starting to drop to less extreme levels. I'm assuming we'll still be able to see how much of a role the presence of phosphates plays in this.
In any case, if we can at least leave the thread open, I can always update the results next spring when bather loads get heavy again. By then we'll probably be using the "pro" grade enzyme product as well.
Thank you to everyone here on PGN, but especially Al & Tom for taking as much time as you have to work with me on this. As we'll likely still be in phone and email contact, we'll summarize our discussions here to share.