To Shock Or Not To Shock.... Or Maybe Even When To Shock?

[Bob Sanders]

I have a fairly high traffic tub. It sees roughly 7 to 10 bathers a day, 7 days a week. It used to be pretty easy to tell when it needed shocking. The water would start to haze over a little.... which was usually about every 48 hours.

However roughly 12 days ago now I drained, installed a better filter system, and a Del MCD-50 high output ozonator. Since then the water has stayed crystal clear in spite of the heavy traffic. (Chlorine levels are being held between 1 and 2). I'm not even having to use a spa ball anymore so the long and short of it is that all my tell-tale signs of necessitating shock treatments that I was used to in the past, are gone. Do I still need to shock even though the water is clear and remains balanced? If so then how often?

[Mark SC]

You only need to shock if you have problems. I would keep the chlorine level higher--at least 3 ppm, but 5 would be better given your traffic. The need to shock arises when the chlorine falls to 0, so keeping the baseline higher will help prevent that.

[waterbear]

What are your combined chlorine readings? This will tell you if you need to shock or not. If there is no CC then you do not need to shock. Ideally you want CC at 0 ppm but in a residential spa CC up to .5 ppm is acceptable. Also, are you shocking with chlorine or MPS? Do you have any CYA in the water? This will determine how high you want to run the free chlorine. However, a FC between 1 and 2 ppm is probably not high enough even for a spa with no stabilizer to handle the type of organic load you are putting in the water, even with ozone. What form of chlorine are you using (stabilized or unstabilized)?

Ozone does not allow you to run a lower FC level. it just lowers sanitizer demand (in some cases) which means you need less to maintain the same level as you would without it. In other cases it actually can raise chlorine demand in a tub.

Remember, just because water is clear it does not mean it is sanitary and cloudy water does not always indicate a sanitation problem that requires shocking.

If you would post a full set of test results (not done with strips) it would be helpful.

[Bob Sanders]

I would keep the chlorine level higher--at least 3 ppm, but 5 would be better given your traffic.

DEL has suggested chlorine can be run at a lower level with its ozonator. So far I have kept it between 1 and 2 and there do not seem to be any issues.

[Bob Sanders]

What are your combined chlorine readings? This will tell you if you need to shock or not. If there is no CC then you do not need to shock. Ideally you want CC at 0 ppm but in a residential spa CC up to .5 ppm is acceptable. Also, are you shocking with chlorine or MPS? Do you have any CYA in the water? This will determine how high you want to run the free chlorine. However, a FC between 1 and 2 ppm is probably not high enough even for a spa with no stabilizer to handle the type of organic load you are putting in the water, even with ozone. What form of chlorine are you using (stabilized or unstabilized)?

Ozone does not allow you to run a lower FC level. it just lowers sanitizer demand (in some cases) which means you need less to maintain the same level as you would without it. In other cases it actually can raise chlorine demand in a tub.

Remember, just because water is clear it does not mean it is sanitary and cloudy water does not always indicate a sanitation problem that requires shocking.

If you would post a full set of test results (not done with strips) it would be helpful.

Combined chlorine (which I am assuming is the same as "total chlorine") hovers between 0 and 1 (a little hard to read since i'm using test strips and the color sort of hovers at the lowest two colors). Granular chlorine with stabilizer is being used.... which kind of bothers me a little... not much direct sunlight these days and as I understand it, it is possible to get a build up of stablizer in the tub.

[chem geek]

There is no mystery here. You normally don't need to shock if you properly maintain the chlorine level and use enough to oxidize bather waste. If you had, say, 8 bathers for 30 minutes 7 days a week, then in a hot (104ºF) tub without an ozonator this would require 14 teaspoons of Dichlor or 20 fluid ounces of 6% bleach or 28 teaspoons of non-chlorine shock (43% MPS) to oxidize the bather waste. I suspect you were using woefully inadequate amounts of chlorine and that is why you needed to shock to "catch up".

An ozonator will oxidize bather waste so that chlorine doesn't have to, but it also oxidizes chlorine itself so an ozonator works best in high bather-load situations such as the one you describe. It is probably handling at least half of the bather waste so the chlorine you are adding becomes enough so that the water remains clear.

As waterbear noted, measuring CC would be an indicator for a need for shocking, but you should measure it at the start of the day since there will most definitely be CC right after a heavy bather-load and such CC will get handled and not be a problem. Remember that monochoramine measures as CC and yet many municipal water districts use chloramination with 1 ppm or more monochloramine which would register as CC (i.e. 1 ppm CC is not really a problem if it is monochloramine -- what is more relevant is that there is also measurable FC since that would indicate that disinfection/sanitation is still occurring while the CC will get oxidized by the chlorine or ozone given some time).

What kind of chlorine are you using in this spa? Is this chlorinating liquid fed by a peristaltic pump? Is there any CYA in the water or is this a commercial/public spa in a county/state that bans CYA for spas?

[Bob Sanders]

Thank you all for the info thus far.

I have no idea how much work the ozonator vs the chlorine is doing but I will say that the inclusion of this mcd-50 has made a WHOPPING difference in water quality. It seems to oxidize just about everything and its grandmother. Quite interesting... about 3 days after I filled the tub the water took on a slight bluish tint. got concerned and called DEL. They said this happens often with fresh fills and it's simply the ozone oxidizing some of the metals from the tap water. They said it would clear in a day or so with running the filters (it did).

No... not a commercial spa... just for my family and myself. It's simply an extremely convenient tub (indoor/outdoor) so it get used A LOT by us.

I have yet to test for CYA (or added). I would imagine there is some in there since I'm using dichlor... but I'm applying so little now.... maybe a couple teaspoons (for 1100 gallons) every other day.

(Chlorine is granular with stabilizer)

[waterbear]

Combined chlorine (which I am assuming is the same as "total chlorine") hovers between 0 and 1 (a little hard to read since i'm using test strips and the color sort of hovers at the lowest two colors). Granular chlorine with stabilizer is being used.... which kind of bothers me a little... not much direct sunlight these days and as I understand it, it is possible to get a build up of stablizer in the tub.

Here is a little chlorine primer for you that might help.

IF you are testing with OTO (liquid with yellow comparator blocks) it only measure Total Chlorine and is not going to do you much good. (Although it is adequate for bromine since we only measure total bromine because bromamines are effective, if not somewhat smelly, sanitizers.)

IF you are testing with DPD (liquid with red comparator blocks) it measures Free Chlorine and Total Chlorine and you computer the combined chlorine by subtracting the FC from the Total Chlorine. (TC-FC=CC)

IF you are testing with FAS-DPD (powder and liquid titirant and it is a drop counting test that does not use a comparator), which is the BEST way to test chlorine it will directly measure Free Chlorine and Combined Chlorine (the two we are interested in) and you can get the Total Chlorine (a pretty much useless measurement in a properly maintained chlorine system) by adding the two together. (FC+CC=TC)

IF you are testing with strips, get a good drop based kit that uses FAS-DPD such as the Taylor K-2006 or the LaMotte 7022). FAS-DPD is FAR superior to DPD testing. IF you already have a Taylor K-2005 or equivalent DPD test kit then get a stand alone FAS-DPD test such as the Taylor K-1515 or the K-1518 is you also use MPS, which tests as combined chlorine unless the interference is removed.

Strips are useless for trying to balance water. They do not have the resolution (TA is a good example since pH control in a spa often requires adjustments of 10 or 20 ppm in the TA), can be difficult to read (as you noted), and some of the tests are just plain inaccurate! (CYA testing with strips is notorious for being inaccurate and strips cannot meausure calcium hardness. They measure total hardness, which is really pretty useless for pools and spas.)

Free Chlorine is the 'good chlorine' that sanitizes and oxidizes. It has very little odor.

Combined Chlorine is the 'bad chlorine' that has combined with ammonia or an amine and is not an effective sanitizer. It has a distinctive 'chlorine smell'. We get rid of it by 'shocking' (superchlorinating).

IF your CC is above .5 ppm you need to shock. (.4 ppm is the threshold for most people to be able to smell chloramines and is the limit for commercial spas and pools in many localities.)

IF you smell chlorine then you need to shock. (assuming you have chlorine in the water. If your TC is very low then you wll not be able to smell the chlorine, even if it is all CC, see above.)

IF the water is cloudy then you may need to shock. (There are many water balance issues that can cause cloudy water and shocking will not solve all of them.)

Once again, ozone does not allow you to run a lower FC level. You still need a fast acting residual sanitizer in the water because every bather, no matter how clean they THINK they are, adds sweat, urine and feces to the water. The first two add a lot of ammonia and amines and the last one nitrogen compounds and fecal bacteria. While ozone can help lower the levels of the first two (and therefore help lower the total chlorine demand) it can only kill what bacteria it directly contacts and it does not have a residual effect in the water. You need to maintain enough active chlorine in the water at all times for the residual effect and the amount you need is determined by how high your CYA is. The higher the CYA the higher the FC level needed to maintain the same ACTIVE chlorine level in the water.

What ozone can do is lower your chlorine demand, or the AMOUNT of chlorine needed to maintain a certain FC level, by oxidizing organics so the chlorine does not need to 'work as hard' and only needs to be the residual in the water. However, as chem geek also pointed out, ozone destroys chlorine and vice versa so it really depnds on tub usage patterns as to whether ozone will for for you or against you with chlorine (It plays better with bromine). In your high usage situation it will probably work for you, btw.

Finally, you are correct that continued use of dichlor will cause the CYA to build up and lower the effectiveness of your chlorine. This is often the cause of pseudomonas outbreaks which is why it is recommended to use enounh dichlor to obtain a 20-30 ppm level and then switch to an unstabilized chlorine source. Of the three available both sodium hypochlorite (bleach) and lithium hypochlorite have the fewest side effects (basically pH neutral on use and they only add salt to the water) BUT there is a big price differential. Lithium is the MOST EXPENSIVE form of chlorine available for pool/spa use. Bleach is cheap and readily available.

If you are starting from a fresh fill you don't even need to test the CYA because for every 10 ppm of chloine added by dichlor you are adding 9 ppm CYA so keep adding dichlor until you have added enough to have added between 20 to 30 ppm FC and your CYA will be in range. A ballpark figure would be to use .5 to .75 oz dichlor per 100 gallons to maintain your FC and when that is used up switch to bleach as your chlorine source and the CYA will be in the ballpark of where you want it. With a CYA of 20-30 ppm you want to maintain your FC at 3-5 ppm (to compensate for the effect that CYA has on chlorine). Only using an unstabilized chlorine without CYA is not a good idea because the CYA acts as a sort of 'buffer' for the chlorine and keeps it from being as aggressive to tub parts, bathing suits, and people.

I know you have been using bromine. Chlorine, is a bit more 'finicky' but once you get the hang of it, not hard at all.

[Bob Sanders]

Thank you for that incredibly detailed explanation. I've actually copy/pasted it into a word document so that I can access it easily for future reference.

I do happen to have a taylor liquid test kit on hand and use it the odd time for a more detailed look. Never knew about the combined chlorine calculation though.... I'll have to look at that tomorrow. The test strips I use (pentair 5 way strips) do measure both free and total chlorine.... but as stated, they can be a pain to read.

As far as water balance goes... I really haven't had to do any at all. It comes out of the tap pretty much balanced around here (although hardness could be a bit higher... it comes out of the tap at about 80), but ph and alkalinity are already in the ball park (7.5 and 80 respectively) and have remained as such since my last fill.

[Bob Sanders]

Did test for CC this morning and it's pretty much 0

Question though.... Will the ozone not simply oxidize the CC? It APPEARS to oxidize just about everything else. (I should make it clear here that the ozone runs 24/7 and the MCD-50 is denoted as "high output")

[chem geek]

As noted in this summary of scientific research, ozone only partially oxidizes the majority of organic compounds in pool or spa water. However, such partial oxidation can create negatively charged molecules that combine with highly positively charged ions (e.g. calcium, magnesium) to have a microflocculation effect that will capture these compounds in the filter. As for monochloramine, the reaction with ozone is slow and it will be chlorine that is more likely to fully oxidize ammonia to nitrogen gas.

As I noted earlier, you were using woefully inadequate amounts of chlorine relative to your bather load and by using Dichlor the buildup of CYA was making the chlorine less effective over time. Had you used the Dichlor-then-bleach method and used the proper amount of chlorine, your water would have been in as good shape as you see it now and would likely have not measured any significant CC prior to your soaks. Of course, for high bather-load spas such as in your situation, ozone is very helpful because it is a great supplement to chlorine for oxidation. As waterbear noted, it reduces the total amount of chlorine you need to add, but doesn't change the required background FC level you need to maintain.

With your ozonator running 24/7 and being of high output, you should make sure that you are able to maintain an FC residual. Ozone will react with chlorine to create chloride and chlorate so will use up chlorine. Because of your high bather-load, the ozone is probably being used more to oxidize bather-waste, but if the ozonator is too powerful relative to the bather-load, then it can end up using more chlorine and make it harder to maintain an FC level. So check the FC level before your soak to make sure it is at least 1-2 ppm. If it isn't, then you need to use more chlorine; if it's too high, then use less chlorine.

[Bob Sanders]

As I noted earlier, you were using woefully inadequate amounts of chlorine relative to your bather load and by using Dichlor the buildup of CYA was making the chlorine less effective over time.

Sorry... maybe I wasn't clear above. Previous to this I was on Bromine tabs with floater, and as for levels... they were kept at the recommended 3 to 5 ppm

[waterbear]

As I noted earlier, you were using woefully inadequate amounts of chlorine relative to your bather load and by using Dichlor the buildup of CYA was making the chlorine less effective over time.

Sorry... maybe I wasn't clear above. Previous to this I was on Bromine tabs with floater, and as for levels... they were kept at the recommended 3 to 5 ppm

And as I stated before, bromine tabs with a floater are only part of the bromine equation. A bromide reserve has to be created in the water first and an oxidizer has to be used also. Believe it or not, chlorine is the best oxidize for bromine since it is not an irritant like MPS and it is also a primary residual santizer, unlike MPS. Also, most bromine tabs do contain a significant amount of chlorine so if a bromide bank is not established the either starts out as a chlorine tub or an undersantizied tub. Even with a high bather load a bromine tub should not be turning cloudy in a day as you stated yours did. Also, bromine should be at a 4-6 ppm level.

What chlorine testing method does your Taylor kit use? OTO, DPD, or FAS-DPD. IF it is an OTO kit is is a 1000 series kit and not what you want. If it is a DPD kit and it is a 1000 series kit it is not what you want. IF it uses DPD and is a 2000 series kit the only one that will test all the parameter you need to test is the K-2005 and you should upgrade the chlorine test to FAS-DPD by getting the stand along FAS-DPD test kit. The difference between DPD testing and FAS-DPD testing is night and day! No color matching, no guesswork and an precision as great as .2 ppm for FC or CC and it directly measures CC. Ditch the strips, they are useless.

[Bob Sanders]

And as I stated before, bromine tabs with a floater are only part of the bromine equation. A bromide reserve has to be created in the water first and an oxidizer has to be used also.

Yes... I believe all of this was done correctly (as per bromine kit instructions)

"On initial fill start with balancing......."

".....adjust floater for 3 to 5 ppm and add 60gm/1000 liters water Spa Shock (mps)...."

I actually have 2 taylor kits.... the K1001 (bought along with my bromine starter kit) and the 1515 which I picked up yesterday (that's all they had in stock)

[waterbear]

And as I stated before, bromine tabs with a floater are only part of the bromine equation. A bromide reserve has to be created in the water first and an oxidizer has to be used also.

Yes... I believe all of this was done correctly (as per bromine kit instructions)

Then it most likely was not done correctly, believe it or not. There is so much misinformation about bromine chemistry, even from the chemical repackagers (since most of them do not make the chemicals but just buy them and repackage them). Arch Chemical/Adantis/Lonza (I think I included all the recent mergers) and Proteam/Haviland seem to be the only companies that "do bromine correctly" with most of their retail brands such as HTH, Leisure Time, Robarb, Rendezvous, and Proteam . (At least they offer the correct products to "do bromine correctly" if you know how to do it and HTH, Leisure time, and Rendezvous do have literature that tells how to properly start a bromine spa.) The Chemtura brand names do not seem to (Bioguard/Spaguard, Spa Essentials, Spa time to name a few).

"On initial fill start with balancing......."

Did it say anyting about adding sodium bromide on initial fill?

".....adjust floater for 3 to 5 ppm and add 60gm/1000 liters water Spa Shock (mps)...."

As I said before, MPS can be used as an oxidizer with bromine BUT it is a known irritant and sensitizer and people do tend to have reactions to it. Also, it is not a sanitizer so choosing an oxidizer that is also a primary sanitizer it a better (and less expensive) choice, IMHO. FWIW, bromine tabs contain both organic bromine AND chlorine since they are BCDMH or1-bromo-3-chloro-5,5-dimethylhydantoin) unless you are using DBDMH (1,3-Dibromo-5,5-Dimethyl Hydantoin) but that is not a tablet but a nugget and requires a special floater with a screen to keep it in the floater.

I actually have 2 taylor kits.... the K1001 (bought along with my bromine starter kit) and the 1515 which I picked up yesterday (that's all they had in stock)

The K-1001 is a residential series DPD chlorine/pH test it. It does not test CYA, TA, or CH which you DO need to test (and strips are just not going to do the job for you) and uses pH reagent R-0014 and the small pH comparator. The K-1515 is only a chlorine test using FAS-DPD. The kit you need is the K-2006, which will test everything you need. Most places do not stock this kit (they stock the K-2005 which is a DPD kit) so it usually has to be ordered from the internet (Amato Industries is repoerted to have the best price) or directly from Taylor. If you are based in Canada the Taylor kits are very expensive compared to the US (the master Canadian distrubutor sets the prices there) but still your best bet and can be ordered from Piscines-Apollo Pools and other Canadian retailers or from the master Canadian distributor, Lowry & Associates in Newmarket, Ontario (905-836-0505). Since you already have the FAS-DPD kit yo can save a bit of money by getting the K-2005 which is identical to the K-2005 but it uses DPD testing. The pH comparator and reagent in the 2000 series kits is different than yours since it is a 44 ml sample size and the resolution is much smaller. It goes from pH 7.0 to 8.0 in increments of .2 and includes both acid and base demand tess (and the acid demand test can be very useful).

just because pH and TA are fine coming out of the tap they are not going to stay that way. Dichlor is acidic on use (slightly acidic when it is applied to the water and the reaction of hypochlorous acid being oxidized to chloride when it acts as a sanitizer is acidic (and your constant ozone will certainly be oxidizing additional hypochlourous acid) so this will have an impact on both your TA and pH, depleting the first and causing the second to drop. Also, the main cause of pH rise in spas is from outgassing of CO2 and the carbonation in spas is from the TA (bicarbonate) of the water. Chlorine is a bit more 'fussy' about pH than bromine, btw.

As far as testing frequency (once water is balanced), test chlorine and pH daily (daily chlorine test can be DPD or strips as long as you are using the FAS-DPD weekly or whenever your daily test indicates that levels are not in range), test TA weekly (and CYA if you are using exclusively Dichlor--and be sure to order additional CYA reagent!), and test CH every 2 to 4 weeks (also CYA every 4 weeks if using the dichlor/bleach method since CYA might drop a bit low if you have a lot of splashout and need to top off frequently so it might need to be bumped up a bit).

[Bob Sanders]

Then it most likely was not done correctly, believe it or not. There is so much misinformation about bromine chemistry, even from the chemical repackagers (since most of them do not make the chemicals but just buy them and repackage them).

Well this is a small printed booklet directly from the SpaBoss line of chemicals:

SpaBoss; A comprehensive Guide To Spa/Hot Water Care

I would be hard pressed to label it as "misinformation".

I think as with anything else there are clear (and different) levels of accuracy depending on how far you wish to delve into the issue in question. Not that I believe test strips are the most accurate means testing.... but they are certainly pretty universally accepted.

As for K2006 kits, I find it both interesting and strange that they be touted as the more accurate kits to get (and I don't doubt it).... but are not readily available. I even checked at Krevco (one of our bigger spa depots in the city). I wonder what this says about the spa industry in general... or maybe what it says about how accurate one REALLY NEEDS to be on such issues?

[waterbear]

Then it most likely was not done correctly, believe it or not. There is so much misinformation about bromine chemistry, even from the chemical repackagers (since most of them do not make the chemicals but just buy them and repackage them).

Well this is a small printed booklet directly from the SpaBoss line of chemicals:

SpaBoss; A comprehensive Guide To Spa/Hot Water Care

I would be hard pressed to label it as "misinformation".

As I said, many repackagers do not understand bromine chemistry and for that matter, will make more money if your water is NOT balanced.

I think as with anything else there are clear (and different) levels of accuracy depending on how far you wish to delve into the issue in question. Not that I believe test strips are the most accurate means testing.... but they are certainly pretty universally accepted.

As for K2006 kits, I find it both interesting and strange that they be touted as the more accurate kits to get (and I don't doubt it).... but are not readily available. I even checked at Krevco (one of our bigger spa depots in the city). I wonder what this says about the spa industry in general... or maybe what it says about how accurate one REALLY NEEDS to be on such issues?

Consider that chemical manufacturers and pool/spa supplies are in the business to sell chemicals and not to keep your water balanced and your money in your wallet. One MAJOR line has a much touted water testing system (that has a 4 letter man's name) that is notorious for overdosing and is, in fact, optimized to maximize dealer profits and not to balance water. In that light is is really that strange that a easy to use test kit that will allow someone to keep their water balanced and minimize the need for unnecessary chemicals would not be more available. It is in their best interest that an accurate, precise, and easy to use kit is NOT readily available. You said to me in a PM that your total sum experience is with your own spa so perhaps it might be time to open your mind to some people with a lot more experience in (and about) this industry. There is a lot of misinformation and myths in the pool/spa industry that persist even after they have been thoroughly disproven. Case in point, "slugging" acid to lower TA vs "walking" acid to lower pH. In reality it does not matter how the acid is added at all! Another case in point, the chlorine/cya relationship has been known since the 70's and has even been published in scientific and trade journals (such as the JSPSI) yet many (most) manufacturers and dealers TO THIS DAY insist that CYA levels do not matter and that CYA levels up to 200 ppm are not a problem (and this is from the same manufacturer who has the water testing system I mentioned above). Interestingly enough, this is also one of the largest manufacturers of stabilizied chlorine and their product lines are found in not only exclusive dealerships with their premium brand but also have brands in the big box stores like Home Depot, Lowes, and Walmart.

[Bob Sanders]

Consider that chemical manufacturers and pool/spa supplies are in the business to sell chemicals and not to keep your water balanced and your money in your wallet.

Well I think that's the nature of ANY manufacturer and it's not just restricted to the spa industry. I'll bet you any money the oil companies are paying the car companies to wind those oil change count-down timers on cars these days, a little tighter than they need to be. But this describes the manufacturers and not necessarily the shop owners. They have the ominous task of balancing supply and demand along with profits and client trust.

When I first started this I went to Crown Spas (in business 15 years) and told the owner "I know nothing, please set me up with a bromine starter kit".... he could have basically sold me the store, but he didn't. In fact there were several chemicals listed in that little booklet that he didn't sell me claiming they weren't really necessary. When I went back later and told him I needed to switch off of bromine because of my little one's bromine rash he again sold me only what was required.

Interestingly enough I asked him what he used on his own personal hot tub and his answer was that he relies very little on chemicals at all these days. Just what is required to balance the water and "very little chlorine" anymore (he couldn't/wouldn't point out exactly how little since Health Canada insists on 3 to 5). He runs UV in combo with Ozone. Reason being is that Chlorine is now a lot like penicillin with respect to the fact it has been used for so long that there are certain parasites that have become highly resistive. Cryptosporidium these days for example lives quite nicely in chlorine at 3 to 5 levels and recent research has shown it to be resistive in chlorine levels up to almost 80ppm. UV and ozone on the other hand kill it immediately. (He did go on to tell me there are also cons to electronic systems too.... but that's another story). These are his words BTW... not mine so don't shoot the messenger.

At any rate... trying to avoid going off on a tangent here... a retailer's motives and that of a manufacture are a bit different. A retailer needs to worry about supply and demand (profit vs overhead) and returning customers (trust). This being the case I would suggest this whole thing revolves more around the customer's want to enjoy a hot tub without the need to be a chemist. Retailers work in a supply and demand world. If the demand for such accuracy was there.... so would the test kits be. And experience.... there doesn't seem to be any shortage of that out there. The question is however... which version of who's experience should one actually believe because what I have learned thus far is that just about every experienced person has a completely different road for you to travel on.

[chem geek]

Reason being is that Chlorine is now a lot like penicillin with respect to the fact it has been used for so long that there are certain parasites that have become highly resistive. Cryptosporidium these days for example lives quite nicely in chlorine at 3 to 5 levels and recent research has shown it to be resistive in chlorine levels up to almost 80ppm. UV and ozone on the other hand kill it immediately. (He did go on to tell me there are also cons to electronic systems too.... but that's another story). These are his words BTW... not mine so don't shoot the messenger.

Fortunately, your dealer wasn't one of those who would sell you extra stuff, but he also didn't carry better test kits. He also probably didn't understand how a higher TA level tends to make the pH rise, especially when one is using certain types of sanitizers (hypochlorite chlorine, for example). A lot of that isn't his fault since his information tends to come from chemical manufacturers and they don't describe the pH/TA relationship nor the chlorine/CYA relationship.

As for what he told you (quoted above), that's just bunk. Parasites have not become resistant to chlorine, primarily because chlorine is a broad-spectrum disinfectant that does not kill through just one mechanism. Yes, Cryptosporidium parvum is a protozoan oocyst that is very resistant to chlorine, but it did not "become" resistant to chlorine specifically and did not do so during the existence of humans. Such protozoan oocysts have thick exterior shells to be able to survive in the harsh environment since they are water-borne pathogens that need to survive until finding a new host. They do not live or reproduce in the water. They only become active in the mammalian intestinal system. And this long-term evolutionary development of protozoan oocysts happened millions of years ago -- long before humans started chlorinating their pools and spas! And because protozoan oocysts do not reproduce in water and because they only get into water from infected persons (in the case of Crypto, through diarrhea), the odds of you getting Crypto in your own residential spa are virtually nil. It is a problem in commercial/public pools and spas where infected persons are not responsible and swim or soak in spite of having illness and can then infect dozens if not hundreds of others, but in residential pools and spas getting Crypto is virtually unheard of. On the other hand, if only UV and ozone are used, then bacteria can grow on spa surfaces since there is no bulk-water disinfectant and they are not circulating through the UV/ozone system. This is why some sort of bulk-water disinfectant is required of which there are only four approved by the EPA for spas: chlorine, bromine, Baquacil/biguanide/PHMB, and Nature2 with MPS (the latter is ONLY for spas and not for pools since hot water temperature is also required).

Your dealer probably didn't tell you that ozone reacts with chlorine thereby increasing chlorine demand in spas that are not used frequently (every day or two). So ozonators are great for high bather-load spas such as those used every day, but they end up costing more in chemicals for less frequently used chlorinated spas. For this latter situation, bromine is a better choice to use in spas with ozonators since ozone can oxidize bromide to bromine thus maintaining bromine levels in between uses.

[Bob Sanders]

but he also didn't carry better test kits. .

Well that's my point.... not many do.

[WuhWuzzat]

Well that's my point.... not many do.

...*sigh*...

I believe that it's Chem + WB's point that it's in the pool/spa store's best interest NOT to carry a test kit that allows you to achieve precise results. You've been told several times by some of the most respected and knowledgable members on this board(as well as others)that using test strips can be wildly inaccurate making proper water balance unecessarily difficult. Why can't you concede this?

[Bob Sanders]

Well that's my point.... not many do.

...*sigh*...

I believe that it's Chem + WB's point that it's in the pool/spa store's best interest NOT to carry a test kit that allows you to achieve precise results.

Sorry but I don't believe that for one single little second. That makes no sense at all. They could just as easily be LOSING money by not carrying the kits while people UNDER TREAT their tubs because of inaccurate numbers. And further more... to believe ALL spa shop owners are dishonest to this degree is TOTALLY ridiculous. In fact I find the suggestion slightly offensive. The people I have been to over the last few months have been nothing less than courteous and honest and don't deserve the kind of blanket statement you throw at them.

As stated we live in a supply and demand world. If the public wanted such kits and were deemed to be big sellers then you could be ABSOLUTELY SURE you would find them all over the place.

[waterbear]

Then perhaps you would be happier talking to your spa dealer than posting on this board because you seems to feel that all our info is wrong and only yours is right based on your vast experience of OWNING A SINGLE SPA!

Then again, I don't expect you to get this point either.

Or perhaps you just enjoy being confrontational since you have been so in several threads now in the 3 weeks (and with some of our MOST RESPECTED members who have a LOT MORE KNOWLEDGE AND EXPERIENCE THAN YOU DO NOW OR PROBABLY EVER WILL (and I am not talking about myself either) you have been a member on here (and considering that you were not able to post for one of those weeks it's pretty amazing that in that short time you are averaging 3.5 posts a day which certainly indicates that you like to see yourself in print online even when you don't have much to say based on knowledge or experience, both of which it is obvious you lack.)

As stated we live in a supply and demand world. If the public wanted such kits and were deemed to be big sellers then you could be ABSOLUTELY SURE you would find them all over the place.

IF the public were educated PROPERLY they would want such kits and that is the reason there are boards like this one so the public can become educated, since the chemical manufacturers and distributors are largely responsible for much of the misinformation that dealers learn and then pass on to the public.

Then again, with your GREAT INSIGHT into the industry based on the one shop that you have been frequenting I am sure you have a quite different view.

To paraphrase an old saying, "you can lead a spa owner to water but you can't make him think".

I think that statement has been proven true here.

You did send me a PM asking me to deactivate your account during the week that you were on moderator preview. Perhaps I should honor that request now since you don't seem to be happy here except when you are arguing with someone knowledgeable on the board. So far your short list includes Dr. Spa, Spatech (the unreal one), chem geek, PreservedSwine, myself, and in the process confused at least 2 newbies that I am aware of. Quite a track record in two weeks of postings!

[Bob Sanders]

Or perhaps you just enjoy being confrontational since you have been so in several threads now in the 3 weeks (and with some of our MOST RESPECTED members who have a LOT MORE KNOWLEDGE AND EXPERIENCE THAN YOU DO NOW OR PROBABLY EVER WILL

You don't seem to understand that it is not my knowledge and experience that is being talked about. I've already admitted SEVERAL TIMES NOW that I have very little experience when it comes to discussing things directly related to spas. What I have stated (and you keep ignoring) is that there are MANY who claim to be experienced all saying very different things and the only thing I'm doing here is QUITE LOGICALLY asking why. You and others on this board seem to want me to believe there is some sort of major conspiracy here with all the spa stores in my city and they're all trying to hide the truth from me. Sorry guy... that's just a heck of a stretch. You call a booklet that I was reading from "misinformation" when you haven't even seen it or read it? You say you're experienced (and I have no doubt of that) but what do you say to an EXPERIENCED shop owner who tells me he believes more in electronic methods these days than chemicals. How am I supposed to know which "experienced" person is the one with more experience? You say measuring CC is important. Well how come Health Canada doesn't say that. They clearly mention free chlorine and the fact that one should follow the instructions on the given labels but they say nothing about CC.

http://www.hc-sc.gc.ca/cps-spc/pubs/pest/_fact-fiche/pool-spa-piscine/index-eng.php

Now I am NOT being or trying to be confrontational. I'm merely trying to gain enough info from all sides so that I can make an informed decision.... that's all.

Then again, with your GREAT INSIGHT into the industry based on the one shop that you have been frequenting I am sure you have a quite different view.

I have not frequented ONE shop but rather quite a few.... and it's the same story.... no such detailed kits. I believe you even stated above that they're not often found in the spa shops. Now I'm terribly sorry but I have a real tough time believing that this is some major cover up that has been arranged by all the spa shops in some back room. I suppose it is possible... but the probability of it is another thing entirely. What's more believable (and logical) is that there simply is not a market for such creatures when there are fast test strips for (lazy) spa owners who would rather spend more time IN the spa as opposed to testing it. Shop owners are not interested in getting stuck with expensive expiration dated test kits that don't sell.

You did send me a PM asking me to deactivate your account during the week that you were on moderator preview. Perhaps I should honor that request now since you don't seem to be happy here except when you are arguing with someone knowledgeable on the board. So far your short list includes Dr. Spa, Spatech (the unreal one), chem geek, PreservedSwine, myself, and in the process confused at least 2 newbies that I am aware of. Quite a track record in two weeks of postings!

Well... healthy debate does bring forth new and different ideas from different perspectives... but if the message you're presently trying to send is "just be quiet and nod your head when being spoken to" then yes... feel free to remove my membership.

[chem geek]

Well how come Health Canada doesn't say that. They clearly mention free chlorine and the fact that one should follow the instructions on the given labels but they say nothing about CC.

:

What's more believable (and logical) is that there simply is not a market for such creatures when there are fast test strips for (lazy) spa owners who would rather spend more time IN the spa as opposed to testing it. Shop owners are not interested in getting stuck with expensive expiration dated test kits that don't sell.

Health Canada in their consumer website page only says that "you must regularly test your water balance for adequate sanitizer levels, pH, total alkalinity and calcium hardness." They don't say anything about testing for combined chlorine (CC) or for cyanuric acid (CYA). You are right about that. However, these Canadian regulations refer to testing Cyanuric Acid while these Canadian regulations refer to Cyanuric Acid as well as Combined Chlorine. In the U.S., the commercial/public pool and spa regulations which are done by state and county all refer to both cyanuric acid and to combined chlorine (maximum 0.2 ppm for the latter) and in Europe the German DIN 19643 standard specifies a maximum combined chlorine of 0.2 ppm.

I agree with you that a primary reason for stores not to carry the more accurate, comprehensive and expensive test kits is that they aren't as popular, mostly due to their extra expense and time for the tests compared to test strips. However, there are tens of thousands of pool and spa users on multiple forums who consistently report horribly inconsistent and inaccurate results from test strips (see this post for a comparison of their resolution, which is poor, not even considering their lack of accuracy) and ultimately get the better drop-based test kits and maintain their pools and spas less expensively and with less trouble. There isn't a financial incentive for pool and spa dealers to tell people the truth about test strips being so bad since the profit from fixing pool problems (in particular) through the sale of many supplemental high profit-margin chemicals (algaecides, clarifiers, flocculants, phosphate removers, enzymes, etc.) is higher than that of a single high-quality test kit. The Health Canada website refers to "calcium hardness", but no test strips measure calcium hardness. They can only measure Total Hardness which includes magnesium.

Now I'm not saying that every pool and spa user using test strips is going to run into trouble -- just that the probability of having issues is higher because they truly don't really know what is going on with their water.