The value of using OTO with dilution?

[CarlD]

Split from this topic for further exploration in The Deep End. JasonLion

Has NOBODY told this poor person how to use a cheap test kit to test higher levels of chlorine?

It's no secret how to do it.
1) Make sure your test kit that uses OTO goes to 5ppm--(and 10 Bromine). You CAN do it with one that peaks at 3 but I think they are difficult and won't buy them.
2) Get a jug of STEAM DISTILLED water from your local supermarket.
3) Add one shot glass of pool water to a clean mixing cup.
4) Add two shots of distilled water.
5) Mix and test THIS mixture in your OTO kit.
6) Triple the results. If you get 3, it's 9ppm. If it's 5, it's 15pm.
7) If you STILL can't get a reading, repeat the process but use 3 shots of distilled and multiply by 4 instead of 3.

This will be good enough until you get the proper FAS-DPD chlorine test.

(PS: This is known as the CarlD "Patented" Shot Glass Method! )

 

[Guest]

Re: Trying to figure this all out! OVERWHELMED!

Carl, over here at TFP we really don't push testing high chlorine levels with OTO because it's only testing total chlorine and not free chlorine. As you well know it is very possible to have very high CC levels and almost no FC in the pool.

 

[CarlD]

Re: Trying to figure this all out! OVERWHELMED!

I respectfully disagree with it on the grounds that if you have no way of getting an FC reading, a TC reading is better than nothing.

I clearly am well aware of the difference between FC and TC--you all know that.

It's your forum, and your rules, not mine. I respect that. I'm just an ordinary poster. I'll make certain I absolutely abide by your rules by not posting at all.

 

[Guest]

Using dilutions with either OTO or DPD (not FAS-DPD) is a viable method when killing algae, particularly if you first raise the pH to about 8.0 to promote the formation of monocloramne which is effective at killing algae. The problem is it will lead a newbie to believe that a cheap OTO test kit is going to suffice for their pool testing needs. You will lose precision with each dilution so it's really only going to give you a 'ballpark' number for your TC levels but it's workable until the algae is dead. You then need to be able to test CC to know when you can stop shocking. This is often above the head of a newbie who's only concern is 'how do I get rid of the green and when can I start swimming again?'

A DPD test kit is going to be more effective with dilutions since it will test both FC and TC than an OTO test kit which can only test TC but still won't give you the precision or ease of testing that an FAS-DPD test can. IF the dilutions are not done correctly then there is testing error and it makes the testing an involved process for someone who is not that proficient in testing their pool.

One only needs to look at the number of posts over at PF where people were trying to clear a green pool with only an OTO test kit and the problems they had because they were just not getting their chlorine high enough and contrast that to people who used FAS-DPD testing to see the problems that can occur with OTO.

 

[JasonLion]

CarlD - waterbear is quite correct that we tend to discourage the use of OTO with dilution here at TFP, but that isn't a hard and fast rule. There are a few situations where I have recommended OTO with dilution.

We are certainly willing to explore the relative merits of the various approaches further to see if the general sense around here that OTO with dilution isn't worth it is valid. The one rule we do have that applies in this situation is that the more technical discussions, such as exploring the merits of OTO with dilution, should happen in The Deep End and then the conclusions can be brought back to the rest of the site.

-----

Using OTO with dilution does have some merit, but more and more I am finding that it distracts more than helps. There are a couple of different issues.

1) People who get over the hurdle of buying a better test kit are nearly always really happy that they did. There seems to be some irrational resistance to purchasing a better test kit, presumably because of the price tag. That is not rational because a better test kit will save more than it's cost in chemicals in the long run. Offering an alternative to a good test kit, such as OTO with dilution, tends to strengthen the irrational belief that a good test kit is not worth it, which frequently means further delays before the complete resolution of the original problem can occur.

2) High CC levels can completely invalidate the results of an OTO test. High CC levels are not common when fighting algae, but they do occur in some cases. Using OTO with dilution will result in completely invalid results when high CC levels are present. The preference at TFP has been for techniques that are trouble free, which means avoiding taking a gamble on the CC level.

3) OTO with dilution is dramatically imprecise. When measuring TC levels around say 15, the OTO test with dilution can be +-6 or worse. While it is possible to aim for levels high enough to be sure you hit 15 even with that imprecision, and so effectively shock the pool using OTO, it wastes chlorine. Further, there are other tests, like the overnight FC loss test, that are simply impossible with that level of imprecision.

 

[CarlD]

CarlD - waterbear is quite correct that we tend to discourage the use of OTO with dilution here at TFP, but that isn't a hard and fast rule. There are a few situations where I have recommended OTO with dilution.

We are certainly willing to explore the relative merits of the various approaches further to see if the general sense around here that OTO with dilution isn't worth it is valid. The one rule we do have that applies in this situation is that the more technical discussions, such as exploring the merits of OTO with dilution, should happen in The Deep End and then the conclusions can be brought back to the rest of the site.

-----

Using OTO with dilution does have some merit, but more and more I am finding that it distracts more than helps. There are a couple of different issues.

1) People who get over the hurdle of buying a better test kit are nearly always really happy that they did. There seems to be some irrational resistance to purchasing a better test kit, presumably because of the price tag. That is not rational because a better test kit will save more than it's cost in chemicals in the long run. Offering an alternative to a good test kit, such as OTO with dilution, tends to strengthen the irrational belief that a good test kit is not worth it, which frequently means further delays before the complete resolution of the original problem can occur.

2) High CC levels can completely invalidate the results of an OTO test. High CC levels are not common when fighting algae, but they do occur in some cases. Using OTO with dilution will result in completely invalid results when high CC levels are present. The preference at TFP has been for techniques that are trouble free, which means avoiding taking a gamble on the CC level.

3) OTO with dilution is dramatically imprecise. When measuring TC levels around say 15, the OTO test with dilution can be +-6 or worse. While it is possible to aim for levels high enough to be sure you hit 15 even with that imprecision, and so effectively shock the pool using OTO, it wastes chlorine. Further, there are other tests, like the overnight FC loss test, that are simply impossible with that level of imprecision.

All your points are excellent. I agree with all of them. With caveats.

Remember that when you are up to your back bumpers in alligators is a very poor time to remember that the objective was to drain the swamp--which is what the desperate person has with a wicked algae infestation.

You will NEVER hear me say that someone shouldn't "waste" their money on a FAS-DPD kit. You know that.

I got my PS-232 from Ben Powell back in 2001 and that was for a little 15'x3' round Intex donut pool--and even then I insisted that it was worth every penny and then some!

People mainly come here and to PF because they are looking for answers to a problem that the pool stores can't solve. They are usually in the middle of a crisis. If they are LUCKY, they have a kit like the WalMart 5-way drop kit, or can get one that day. They SHOULD order a FAS-DPD kit, whether from here, Taylor or Leslie's. But in the meantime what are their alternatives?
[Edit by SeanB - Carl, I have explained this to you on more than one ocassion - the tf-100 is from tf testkits, and NOT "here" at TFP. TFP does not sell or profit from the sale of duraleighs kits. We just happen to think it's the best overall residential test kit.
[Addition by Carl: My apologies, Sean. Of course you are right--I keep forgetting because the name TF-100 is always looking like "TroubleFree" to me. And you do have a link to it but not to Taylor's or Leslie's, so it's a natural mistake. It's Duraleigh who sells them, not you. Sorry again.]

1) Test Strips--only now, after many years can I read a Hach or LaMotte strip (the only really reliable ones easily available) and get a reasonable idea of my FC, TC, pH, TA and CYA. In the ball park, but no better. For a newbie? They are worthless next to drop-testing. We all know that.

2) Pool Stores (who then try to intimidate them into buying clarifiers, phosphate removers, calcium increasers, and bags and bags of something called "shock"). But you have to get to them when they are open. I'll bet if you are there 2 to 3x a day they'll kick you out if you aren't buying stuff.

3) OTO Dilution

I understand that you don't want people to rely on OTO dilution as their main tool--clearly I've indicated that. But you cannot protect people from themselves who refuse to listen and learn. I, for one, am willing to put in hours helping someone who doesn't understand the steps but is TRYING. I try to simplify it and break it down.

But if a person refuses to follow guidance and keeps running back to the pool store and throws in all the garbage (see above) they sell him, against my advice, well, there's nothing I can do for him.

I had a dentist down in Northern Virginia who had a poster on his wall that said something like: "There is nothing the doctor can do that the patient cannot undo".

 

[frustratedpoolmom]

I can't resist the urge to chime in. I have seen the dilution recommended on this forum on a number occassions, in situations where they are waiting for a better test kit or they can't make it to a pool store. It's always given with the disclaimer that it's not entirely accurate and only as a stop-gap while waiting for a better kit...and I totally understand the hestitation to recommend it for the stated reasons.

I agree, many of the newbies are looking for the quickest way to clear water. They don't mind spending a fortune on pool chems but ask them to spend $75 on a test kit and they balk. I was one of them. Believe me I regret it, and I wish the FAS-DPD test that came with the TF-100 had a "swamp Option" that gives you double to reagents than a normal kit....LOL

 

[JasonLion]

But in the meantime what are their alternatives?

The fourth alternative is to simply wait till the new kit arrives. It doesn't happen every time, but frequently enough all of the steps undertaken prior to getting a good quality kit are simply wasted money and effort. If you don't add large enough quantities of chlorine quickly enough the algae grows back and you can easily end up right where you started. Another way this can happen is when the new test kit shows some factor that had not been suspected previously, such as PH way off or CYA level way high, that was preventing the prior efforts from working.

 

[CarlD]

But in the meantime what are their alternatives?

The fourth alternative is to simply wait till the new kit arrives. It doesn't happen every time, but frequently enough all of the steps undertaken prior to getting a good quality kit are simply wasted money and effort. If you don't add large enough quantities of chlorine quickly enough the algae grows back and you can easily end up right where you started. Another way this can happen is when the new test kit shows some factor that had not been suspected previously, such as PH way off or CYA level way high, that was preventing the prior efforts from working.

This is where I strenuously disagree. Waiting when you have an algae bloom is tantamount to giving up and giving in to algae WHEN YOU DON'T HAVE TO! For example: The WalMart 5-Way drop kit gives you pH, T/A, CH and CYA in addition to OTO that goes to 5ppm. It costs $12-$15 and, if your WalMart store has it, you can have it that day while waiting, waiting, waiting for your mail-order FAS-DPD.

Besides, with a TC number and YOUR bleach calc or my Rule-of-Thumb you can get a decent ballpark guess at how much bleach/LC you need. It's not random and in the dark, it is less accurate, but it STILL can be effective. Combining it with a run to the pool store to have it checked every couple of days and you are no longer guessing if your TC is totally CC or not. Even a test strip will show you that--if the TC is dark and the FC is white you are facing a CC problem.

I believe in simple, effective solutions to get the job done and get people back in the pool as fast as possible, safely. I don't believe in waiting until you have the perfect combination of tools.

Or course it's best to have the correct tools, but when you don't, you just may have to McGyver it to get yourself close. I see nothing wrong with that.

When I moved South from Binghamton, NY, where I was working as a carpenter after UG school, a master carpenter there gave me some sound advice to take with me: He said people have different ways of doing things from what I had learned from him. It didn't make them wrong. Be open-minded to what works.

I have carried that through grad school, and my career for the last 30+ years.

 

[JasonLion]

Waiting when you have an algae bloom is tantamount to giving up and giving in to algae

An interesting choice of words. I don't think of it as "giving in" at all. I think of waiting a few days as not allowing the algae to control my life. Of course, both of those are value judgements, and have little to do with the practical task of cleaning up the algae.

The first thing to keep in mind is that we don't get into this situation unless the "traditional" method of fighting algae has already failed. Frequently enough one can toss in enough chlorine to bring the pool to shock level and the algae will all die. But if that was going to work, it would have worked already, before anyone comes to TFP to ask for help. The average person asking for help has already been putting significant amounts of chlorine into the pool for days or weeks to little effect. Some drastic change in procedure is required.

My approach to fighting algae calls for frequent chlorine additions, as often as every half hour. By focusing some concentrated time on the algae it can all be killed in a day or two in most cases. But doing this requires preparation. A substantial amount of chlorine needs to be on hand. A block of time must be located in people's busy schedules. And a proper test kit must be obtained. All of these elements work synergistically to transform a week(s) long algae nightmare into a simple mechanical problem to be resolved so we can get back to swimming.

This approach has several advantages. First, it happens on my schedule instead of the algae's schedule. I figure out when I have time to deal with the algae. The approach commonly suggested at PF in the past often results in adding chlorine twice a day during rushed moments stolen from the middle of busy schedules. If I take the time to plan and schedule, I have the time to wait for the test kit to be delivered. Waiting till I have a real block of time to deal with the pool and all the proper equipment on hand is better for me and will use less total chlorine and quite possibly less total calendar time.

Second, it teaches people to be methodical. I encourage planning and focused effort. Obtaining the proper tools is part of that. Third, using a good quality test kit helps teach people to depend on their own testing. Anyone posting in the deep end probably knows how to use a test kit and could get by with an OTO kit if they really had to. But for a complete novice, dealing with the additional steps of dilution only to get an imprecise result that can't be completely trusted is not a way to build confidence.

The people who this whole discussion apply to have already spent at least days, probably weeks, trying to solve their problem. Pausing for a few days to wait for the test kit to arrive is not going to make much difference to the algae. The algae is already doing just fine. It is the pool owner who needs help. Talking a break, getting properly prepared, and then killing all of the algae in a single day with the right tools is a wonderful way to get them into a new mindset and turn around not just the current algae problem but their entire approach to caring for their pool.

 

[CarlD]

What you are advocating is a totally different approach from one that has been proven time and time again over many years at Pool Forum. The PF approach is not a faulty approach. It works if it is followed correctly, despite your implication otherwise. People who come here with failures have, almost every single time not followed the PF approach.

However, I don't discount your approach, not at all. I'd even like to try it out-- and expect it may well work. Last bloom I had I hammered several times that day and in 24 hours my pool was clear. Yes, it was a minor bloom, but a day later the pool was fine. So I see nothing to criticize in the "Spend all day hammering it" approach.

But you are advocating (yet again) a single, solitary NEW approach and nothing else. Sorry, Jason, but the tried-and-true PF method is the Gold Standard which means any other method must be compared to it and shown to work at least as well or better. I'm not saying it won't, nor do I see any reason why it won't, but it is YOUR approach and you are demanding that everyone one else not only use it, but adapt their whole life style to your approach.

I kind of feel like Steve Jobs is here: "If I didn't include it in your iPod or iPhone you don't need it. If you think you need it, you need to change your lifestyle because your lifestyle is wrong and I am right."

Second, it teaches people to be methodical. I encourage planning and focused effort. Obtaining the proper tools is part of that. Third, using a good quality test kit helps teach people to depend on their own testing. Anyone posting in the deep end probably knows how to use a test kit and could get by with an OTO kit if they really had to. But for a complete novice, dealing with the additional steps of dilution only to get an imprecise result that can't be completely trusted is not a way to build confidence.

Can you hear yourself? The tried-and-true PF method requires you to be methodical, disciplined and planned out. Otherwise it doesn't work--those are our failures. They didn't follow the instructions.

Look, your approach should be able to live along side the older, PROVEN one. Why does it have to be "My Way or The Highway" with everything ancillary with it (like "don't use the OTO dilution method if you are stuck")

And if you think the classic PoolForum method doesn't work then this discussion, for my part, is over.

 

[duraleigh]

Well, Carl, sorry to glom on and hurt your feelings but the OTO dilution method is an innaccurate and almost unusable way of measuring chlorine above a 50% dilution.

Have you ever tried it? It simply doesn't work......the results are just too vague to be effective.

The green pools got that way thru "weeks and sometimes years of neglect" (quote from BP) and it got that way because of the helter-skelter approach to managing their water in the first place. To encourage anyone to continue their half-way measures of pool maintenence simply encourages them to continue their old habits of getting by.

Whether you use Jason's approach (I don't) or not, I think it is a disservice to newbies to encourage them to "get by for now"......that's how they caused their green pool in the first place

 

[SeanB]

Nothing to add here as you all have it well in hand other than to point out what Dave (duraleigh) won't in regards to Carl's "wait and wait" comment about ordering a kit. While others in the past have taken weeks and months to ship kits, Dave sends his out the same day when ordered by 2pm. It's not unusual for people to get them the very next day. So when Jason says they may be better off waiting for their kit to arrive, he's not talking about more than a day or two at most.

 

[CarlD]

Well, Carl, sorry to glom on and hurt your feelings but the OTO dilution method is an innaccurate and almost unusable way of measuring chlorine above a 50% dilution.

Have you ever tried it? It simply doesn't work......the results are just too vague to be effective.

Sure have. Worked just fine. It's vague but I expected to be "ballpark", not "17.0567 ppm". That's what makes the shot-glass method good--it's an easy way to accurately measure amounts. But don't use it if you don't like it.

The green pools got that way thru "weeks and sometimes years of neglect" (quote from BP) and it got that way because of the helter-skelter approach to managing their water in the first place. To encourage anyone to continue their half-way measures of pool maintenence simply encourages them to continue their old habits of getting by.

Nobody is encouraging anybody to continue "helter-skelter". Please don't put words in my mouth. Are you saying that the tried-and-true approach I have advocated for years doesn't work? To that I'd say: Prove it. Period.

Whether you use Jason's approach (I don't) or not, I think it is a disservice to newbies to encourage them to "get by for now"......that's how they caused their green pool in the first place

I don't follow your logic. They ended up with a green pool because they either followed a pool store's advice, or their brother-in-law's advice, or they didn't follow anybody's advice and were fumbling around, guessing in the dark. One thing is clear: They certainly didn't follow my advice, your advice, or Jason's advice. I know you know how to clear a pool. And you know I know how to clear a pool!

I defy ANYBODY to show where I've done a disservice to newbies anytime, anywhere, here or at PoolForum. That's flat-out nonsense and you know it!

 

[CarlD]

Nothing to add here as you all have it well in hand other than to point out what Dave (duraleigh) won't in regards to Carl's "wait and wait" comment about ordering a kit. While others in the past have taken weeks and months to ship kits, Dave sends his out the same day when ordered by 2pm. It's not unusual for people to get them the very next day. So when Jason says they may be better off waiting for their kit to arrive, he's not talking about more than a day or two at most.

Well, it's very nice to know that if someone buys one of duraleigh's kits it will arrive within two days. I gather Dave is selling very nice kits--I've even recommended them as one of the three alternatives, Taylor and Leslie's being the other two. I don't have one because I already have a PS-232, a PS-233, and a Leslie's DPD Full Service Kit paired with a Leslie's FAS-DPD/ Monopersulfate test.

 

[JasonLion]

By "traditional" I meant pool store, not PF. I am sorry if you misunderstood that. The pool store/traditional approach is to add a fixed amount of chlorine and hope it works, wait a few days to see if it worked, and if it didn't repeat. No water testing of any kind is involved.

I have a great deal of respect for the PF approach, which works very well most of the time and at least works the rest of the time. The one problem with the PF approach is that it can result in long drawn out battles where chlorine additions are running only very slightly ahead of algae growth. That doesn't happen most of the time, but it does happen with some regularity.

We have a very tricky challenge when dealing with novices. There is so much detail to take in that they are invariably overloaded with information. Some choices need to be made about what options to present at first or novices will often become overwhelmed with information and they will ignore all of it, simply give up, or choose some undesirable path that they don't really understand.

This is a key point as it relates back to what you were saying. If we offer too many choices to a single novice they get overwhelmed. It isn't one choice is best for everyone. It is one choice is best in this situation.

I don't only suggest my favorite approach. Depending on the situation I may suggest any of several different approaches. In each individual situation I normally only offer one choice, but it isn't the same one I might use in different situations. I remember a thread recently where I suggested adding chlorine based on an OTO test reading above or below 5 that you commented on. As frustratedpoolmom pointed out, I have suggested using OTO and dilution in other cases.

those are our failures. They didn't follow the instructions.

To me, this is really the key to everything. How can we teach so that they listen? There are so many things going on, conflicting advice from the pool store, information overload, strong emotional reactions to a green pool, lack of self confidence, incomplete information, difficulty trusting an Internet source, and on and on.

I try to make things clear, simple, reliable, and if followed to provide rapid improvement of the pool. If you present a whole menu of options the message is far more likely to be lost. If there are too many steps they will often give up in the middle and start doing what the pool store said or something they invented themselves that makes even less sense.

The FAS-DPD chlorine test offers so many advantages and the price is reasonable given the cost of everything else to do with a pool. We tend to focus on getting FAS-DPD because it just makes sense. When you have a clear choice like that, some of the alternatives will naturally get less "air time". Factor in the information overload issues and wanting to present the simplest possible picture and it often comes down to the same one choice in many different situations, but not every situation. A very similar thing happens over at PF where people are often practically chanting "bleach bleach bleach" to the virtual exclusion of other chlorine sources because bleach is almost always the best choice.

People consistently don't listen when we tell them how great it is to have a FAS-DPD test. The "intermediate" people, the ones with recent "conversion" experiences, tend to get a little loud about the need for a top quality test kit because they see novices not listening and have very fresh memories of how much of a difference it made to them.

 

[CarlD]

By "traditional" I meant pool store, not PF. I am sorry if you misunderstood that. The pool store/traditional approach is to add a fixed amount of chlorine and hope it works, wait a few days to see if it worked, and if it didn't repeat. No water testing of any kind is involved.

Thanks for clearing that up. We both agree the Pool Store approach fails and wastes money.

I have a great deal of respect for the PF approach, which works very well most of the time and at least works the rest of the time. The one problem with the PF approach is that it can result in long drawn out battles where chlorine additions are running only very slightly ahead of algae growth. That doesn't happen most of the time, but it does happen with some regularity.

I don't know how regularly it fails except when somebody didn't include P.O.P.P.--Pool Owner Patience and Persistence. In fact, the ONLY failures I know about are either not following the procedures laid out, or a mis-diagnosis (ie, the green is from copper, not algae). It even works for Bacq conversions.

We have a very tricky challenge when dealing with novices. There is so much detail to take in that they are invariably overloaded with information. Some choices need to be made about what options to present at first or novices will often become overwhelmed with information and they will ignore all of it, simply give up, or choose some undesirable path that they don't really understand.

Agreed. I am CONSTANTLY trying to simplify what people need to know.

This is a key point as it relates back to what you were saying. If we offer too many choices to a single novice they get overwhelmed. It isn't one choice is best for everyone. It is one choice is best in this situation.

Of course you want it simple. But what a panicky newbie wants is action or they'll spend a fortune on a service that will milk them like a Tammany pol.

I don't only suggest my favorite approach. Depending on the situation I may suggest any of several different approaches. In each individual situation I normally only offer one choice, but it isn't the same one I might use in different situations. I remember a thread recently where I suggested adding chlorine based on an OTO test reading above or below 5 that you commented on. As frustratedpoolmom pointed out, I have suggested using OTO and dilution in other cases.

OK, I'll take the position that you sounded rigid only in the context of THIS discussion.

those are our failures. They didn't follow the instructions.

To me, this is really the key to everything. How can we teach so that they listen? There are so many things going on, conflicting advice from the pool store, information overload, strong emotional reactions to a green pool, lack of self confidence, incomplete information, difficulty trusting an Internet source, and on and on.

I can tell you that we have had very, very few people who couldn't follow our instructions. Usually,they are panicking and can't figure out whether to follow our instructions or the Pool Store Trolls. I can't tell you HOW many times I've said "Take a deep breath. Then do 1).....2)....3).... etc. very simply.

I try to make things clear, simple, reliable, and if followed to provide rapid improvement of the pool. If you present a whole menu of options the message is far more likely to be lost. If there are too many steps they will often give up in the middle and start doing what the pool store said or something they invented themselves that makes even less sense.

I think we are in agreement here again.

The FAS-DPD chlorine test offers so many advantages and the price is reasonable given the cost of everything else to do with a pool. We tend to focus on getting FAS-DPD because it just makes sense. When you have a clear choice like that, some of the alternatives will naturally get less "air time". Factor in the information overload issues and wanting to present the simplest possible picture and it often comes down to the same one choice in many different situations, but not every situation. A very similar thing happens over at PF where people are often practically chanting "bleach bleach bleach" to the virtual exclusion of other chlorine sources because bleach is almost always the best choice.

People consistently don't listen when we tell them how great it is to have a FAS-DPD test. The "intermediate" people, the ones with recent "conversion" experiences, tend to get a little loud about the need for a top quality test kit because they see novices not listening and have very fresh memories of how much of a difference it made to them.

Jason, you KNOW you are preaching to the choir here. I DO believe that, of course, there's nothing better out there than the FAS-DPD Chlorine test and it's the best to have. I've been using it as my Gold Standard since 2001.

 

[frustratedpoolmom]

I was going to add to my earlier post

"I'll get the popcorn, this is gonna get interesting." Now I wish I had.

Something's in the water.....

 

[cscooper]

And more than one year later, I'll chime in. When you're told that you're going to host a 4th of July party in less than a week, and you've been battling green crud in a biguanide pool for more days than you'd care to re-live, you start spending a lot of time on line looking for answers. . . . I didn't have the time to wait for the "right" test kit. I'm so glad I found the posts that explained how to use the Wal-Mart $15 number while I was waiting. If that hadn't been an option, I would still be pouring $$$ into the pool store in hopes of an answer. I earned a degree in Chemistry more than thirty years ago and never worked in the field. But I know how to do arithmetic and such. I got the highest grade in analytical chemistry even though I was the only one in the room who coudn't afford a calculator (slide rules make you think).
Those that insist that no-one talk about how to use OTO test kits because the great unwashed will do it wrong need to climb down off that high tower of knowledge and learn how to communicate with the rest of us.

 

[SeanB]

No one is saying any such thing. There is a difference of opinion as to the effectiveness of this method, especially at higher dilutions. The recommendation to get a good test kit is a good one.

There has been no suppression of discussion - you are free to post just as you are now. You can preach OTO dilution from the rooftops if that is what you want to do - no one is stopping you. However, as a collective, we simply pay attention to what we recommend on a broad scale and try to balance our replies with what we think is going to help the greatest number of people. Sure, your short term dilemma MIGHT be helped with the dilution method, given you aren't going too far with it and get a somewhat accurate result, but it is a fair argument, that delaying your purchase of a better kit, from any source, is going to delay your long term success. If you had no test kit at all, you MIGHT be better off getting your water tested at the pool store, but you aren't going to see us recommending that as a first choice either.

I'm sorry if you misinterpreted this discussion to mean that we don't allow alternative methods. We often have this sort of thread where we discuss, as a group, what methods we think will do the most good. Your input is welcome.