Acid and Base Demand tests: Useful or Not?

[chem geek]

When lowering the pH in my pool, either just to get the pH lower or when doing the TA lowering procedure, I have a choice. I can calculate how much acid I need to have accurately using my spreadsheet or I can use the acid demand test in my Taylor K-2006 kit. I've done both, but over time, I tend to just use the acid demand test because it's there and it's easy. Eventually though, I just know how much I need to add (for regular lowering of pH, that is).

The other time the acid and base demand test is useful is when one is unsure of the pH reading. The acid and base demand tests let one move the pH color up and down to see where the pH might have been. I did that in the early days until I got used to the pH test though now I don't see the need for it anymore.

[PoolDoc]

The other time the acid and base demand test is useful is when one is unsure of the pH reading. The acid and base demand tests let one move the pH color up and down to see where the pH might have been.

Yes. I'd forgotten about that one, but I've used that on occasion as well. And, that is a valid use.

The other issue, of determining how much acid to add, from a PoolForum point of view (what to tell newbies) rather than a personal view (what I might myself do), I strongly prefer a standard dose of acid or base, followed by a test, followed by a re-dose.

Among many other things, I think handling it this way is easier to learn and tends to indoctrinate newbies into the need to manage their pool on a regular basis.

[waterbear]

2 things:
First. this post was split at my post trying to explain the confusion in this thread about the K-1005, K-1000, and K-2006 AND to clarify that both R-0004 and R-0014 pH reagents contain the chlorine neutralizer but are at different concentrations because of the comparator size and NOT that one has chlorine neutralizer and one does not (a bit of misinformation I have seen on this forum too much for my comfort level and I correct whenever it appears, last time was with AnnaK--not sure where it started or who started it) and, IMHO, this was useful info in the OP's thread since he was asking about the k-1005 test kit, which, other than the smaller comparator, which only has an effect om pH and demand tests, is otherwise functionally equivalent to the K-2005 so he really just needed the stand alone FAS-DPD kit.

The only other people besides myself that gave the OP accurate info on their question were giroup01 and BigDave. Even you dropped the ball, Ben, when you referred to the K-2005 instead of the K-1005. Carl, I don't know where your discussion of the K-1000 came in but your post was just wrong:

Add that to the K-2005 and you have the K2006. The K-1000 OTO test kit from Taylor upgrades the OTO and pH test to the same as the K-2006,
The K-1000 has exactly the same pH test as the K-1005 and included both acid and base demand tests. The pH test in the K-2005 and K-2006 is different and while not haveing as wide a range does have geater precision on the pH and demand tests. Neither the K-1005 nor the K-2005 have OTO, they both use DPD and are identical in this test. The K-2006 also does not have an OTO test. It has a DPD-FAS test.
and includes R-0014, rather than R-0004 for the pH test. R-0014 includes a chlorine neutralizer so it can read accurately in higher chlorine situations Both pH reagents have chlorine neutralizer as I stated before. (Chlorine makes pH read high). list on the K-1000 is about $10.

If you have the K-1515 and K-1000, the only other tests you need are the T/A, CYA, and CH tests (acid and base demand are worthless).
The OP had a K-1005 which has exactly the same TA, CYA, and CH tests that the K-2005/2006 have!

Carl

Even if someone is not familiar with the different test kits put out by Taylor a quick search of their website or even just putting K-1005 as a search term in Google would give you the info on that kit in question and the tests that it has.
IMHO, the first post of this thread should have stayed in the original thread since it directly addressed what the OP was asking about, the K-1005 iCare kit and clarifying some of the misinformation that was posted concerning the OP's question.

Second:
As far as demant tests, I already stated that they acid demand test is very useful when lowering TA.

Acid and base demand tests are NOT worthless. In fact they are quite useful when lowing TA

With high TA we all know it will take more acid to lower the pH to our target of 7.0 than with a lower TA. The acid demand test is a tool that will somewhat shorten what is a lengtly procedure.

For example, in a 10K pool with 'normal' TA of 100 ppm it takes just a bit over a quart of muriatic acid (in fact, 1 qt and 10 oz.) to lower the pH from 8.0 (not an unrealistic number for pH when the TA is high, btw) to 7.0 while in the same pool with a TA of 300 (not an uncommon number for someone who has problems with high TA fill water) it takes just under a gallon (115 oz.). General rule of thumb is to put a pint to a quart of acid in (for 10k gallons), wait, and test pH until it is where we want it. This makes what is a lengthy procedure even longer. If we do a demand test we can add our gallon of acid and start aerating. As pH rises we need to continue adding acid, if we do a demand test we know how much is needed to get us back to 7.0. In my own experience this cuts SIGNIFICANT time off what is needed to lower TA.

As far as base demand tests, We sometimes get people who have been using trichlor and have crashed their pH and TA. The general rule is to add half a box of borax and wait and test pH. We all know that it can sometimes take several boxes. With a demand test they will know how much soda ash is needed and it just so happens that they will need very close to exactly twice the amount of borax. In fact, it is so close we can just tell them to put in twice the amount of borax as soda ash.

If someone does not have a demand test then small doses and 'creeping up on the target' is the way to go but if we have testing at our disposal (and even many of our new members seem to have a K-2005) then why not use it?

As far at that goes, if we know that we need to increase the CYA by 40 ppm in a pool why are we telling people to add only half the required amount and, once again, make a lengthy process even longer?

I hope I have not stepped on anyone's toes with this reply but I invite any of you to find fault with what I said and post it.

[BigDave]

Id like to throw this 2 cents in: In the case that I need to use Muriatic Acid (I haven't yet), I'd like to know about how much to buy. I would gladly pay just as much for a quart that I need rather than a gallon and have to store the remainder.

[PoolDoc]

I just realized something.

Carl (and I) think about A/B demand testing from the point of view of trying to teach newbies to use the test, adjust with small doses, test again method ("the TATA method"? ) . . . AND keeping the NUMBER of things tested and taught to a minimum. If a newbie follows the TATA approach, they'll never (or almost never) need the A/B test.

Some of this comes from my background, controlling pH in commercial pools with acid feed, rather than slugged doses.

Evan, you have worked a lot with pool store walk-ins, where you are FORCED to use a large 'fire and forget' doses, because you have no idea if they'll come back. In THAT environment, A/B testing would be almost essential.

And of course, Richard instinctively approaches pool testing from the "how can I acquire the greatest possible amount of analytical information about my pool's water"? Obviously, A/B testing would be a component in that.

So I think what's happened here -- in part -- is we were all speaking from different perspectives, without noticing it. So, now I'm trying to 'notice it'.

[waterbear]

I just realized something.

Carl (and I) think about A/B demand testing from the point of view of trying to teach newbies to use the test, adjust with small doses, test again method ("the TATA method"? ) . . . AND keeping the NUMBER of things tested and taught to a minimum. If a newbie follows the TATA approach, they'll never (or almost never) need the A/B test.
And in the process some of them get very frustrated since it takes so long and they go back to the pool store for their "miracle in a bottle"! Most pool owners, as you well know, do not have a lot of POP. If we have a tool at our disposal (since newbies are now getting the Taylor kit with the demand tests in them so they have them) to shorten the time why not instruct them to use the test when it is appropriate (such as the example I gave above in lowering TA, which is a common scenerio)?
Some of this comes from my background, controlling pH in commercial pools with acid feed, rather than slugged doses.
And this I more than appreciate since I also worked at a commercial facility with acid feed pumps that needed to be adjusted in very small increments. However, since we did test the water 3 times a day in each of the pools, hot tubs, and play areas we had a LOT of data for making the adjustments! Are we expecting the same from a home pool owner? I know I don't want to test MY pool three times a day or more to get the pH where I want it. If I have a 'ballpark amount" to get me very close that would be much better! I can then make whatever small adjustment (if any) is needed the next day.

FWIW, there are times when the TATA (test, adjust, test, adjust) approach is the only way such as with SWCGs when the owner is trying to adjust the cell output to maintain a specific FC level.
Evan, you have worked a lot with pool store walk-ins, where you are FORCED to use a large 'fire and forget' doses, because you have no idea if they'll come back. In THAT environment, A/B testing would be almost essential.
However, I was using Demand tests way before I did the pool store gig. I was the one who dug the demand tests out of storage so I could use them. No one else in the store knew what they were for. They just did the computer read out and handed it and the attached shopping list to the customer!
And of course, Richard instinctively approaches pool testing from the "how can I acquire the greatest possible amount of analytical information about my pool's water"? Obviously, A/B testing would be a component in that.
You seem to forget that I have a similar chemistry background to Richard and tend to do the same with my own pool. Then there is my many years worth of experience with reef aquarium keeping and water testing which is not that dissimilar to pool testing in many ways.
So I think what's happened here -- in part -- is we were all speaking from different perspectives, without noticing it. So, now I'm trying to 'notice it'.

I just think that blanket statements like 'demand tests are useless' are not beneficial (and I drank that koolaid when I was trying to help 'someone' promote their testkit business even though in private conversations I suggested including demand tests because they can be useful. However, this kit was being modeled (an exactly copy?) after another kit that had been available and this 'someone' wanted their kit to be the same. I agree that the demand tests can be considered "advanced" but we do have many users who "graduate' to that level quickly.

[PoolDoc]

OK.

Now, on to the hard part. This thread has provoked a certain amount of uh-h, 'response' in my email box. So I figure I need to wade in a bit.

Evan, you were correct that I confused the K2005 and the K1005. I'm didn't even recall that there WAS a K1005. And, without digging more than I'm willing to right now, I'm not sure what's the case regarding sample sizes and all that, so I'm happy to defer to you.

"Useless" is not the way I'd chose to describe A/B testing.

However, when you wrote

With high TA we all know it will take more acid to lower the pH to our target of 7.0 than with a lower TA. The acid demand test is a tool that will somewhat shorten what is a lengtly procedure.

I'll agree or disagree, depending on how you define "somewhat". My inclination is toward "somewhat" equals "not significantly", and especially in the context of some new to testing (like redtickbeer") an unnecessary complication.

All in all, I'm still convinced that - with a few exceptions -- TATA is the way to go with most PF users, and especially newbies.

We struggle CONSTANTLY with having to balance the need to give instructions that will work if done correctly with instructions that can be followed by confused newbies.

There are many, many significant treatment tools I mention rarely or NEVER, because it's not generally applicable here. For example, I rarely mention (and only with lots of red cautions), direct pre-filter additions of cal hypo to the circulation stream, even though it will
+ remove metals
+ dramatically improve clarity in heavily used pools
+ remove oils and gunk
+ 'test' filters for proper function
+ auto-balance pH, CA, & CH
+ and more.

Why not? Because it's too complicated and depends too much on following the instructions exactly AND because if common sorts of mistakes are made, DANGEROUS results will follow.

Likewise, I've hardly ever mentioned using peroxide and copper for instant (1-day) cleanups of swamps with 4" of sludge on the bottom. Why? Because, even though it's worked EVERY time I've tried it, I haven't worked out doses, and don't know if it works everywhere, and don't want to have to explain all the problems of clean up copper (with no cal hypo!).

So, when Carl and I say A/B testing is not very useful (Carl went further than I would in saying it was "useless") that's a viewpoint I consider to be correct on PF . . . when you keep in mind that our audience is newbies. For a few of us, PF is an outlet or entertainment or even a life interest. But for most people here, PF is a resource that's intended to help them get the chemistry stuff out of the way so they can ENJOY their pool.

In that context, the complication of A/B testing is of questionable value . . . and the question is, "Does it add more value than complication?", since it obviously adds both value and complication. My judgement is, that it adds more complication than value.

There's some background here.

Having worked with lifeguards for years, trying to get them to test pools, I've discovered regular and frequent is MUCH better than regular and infrequent. In other words, it's easier to get the guards to test the pool 1x per day than 1x per week.

Why?

Habits get build with repetition and lost with time in which no repetition occurs. There's a sweet spot that works better than others, and a 1x per week activity is outside it. It is my experiences with lifeguards, and my judgement with homeowners, that they need to test 1 - 2x per day IN ORDER TO GET INTO THE HABIT.

This is one reason I like the K1000, which allows cheap 1 - 2x per day testing.

But . . . A/B testing will never be learned that way, since it's intrinsically of episodic value: you only need it, when things have gone wrong. So, if you teach new users who come to PF to use A/B testing, instead of TATA, you have given them a skill that won't have value until the NEXT time something goes wrong. But, if you teach them to deal with the problem with TATA . . . that skill (and HABIT) simply roles on over into regular pool ops.

I still believe this is a HUGE functional benefit, but again only from the point of view that we are trying to help folks OPERATE their pool in the simplest way possible, with the lowest achievable learning curve.

Or, in other words, K.I.S.S.

Evan, I recognize that A/B testing can occasionally have value. I think it might be worthwhile to have a reference-able page explaining how to do it, so that when people come in with high TA or unknown low (or high) pH we can say:
#1 - do TATA, but check this A/B page out, since it might help you, in your particular situation.
#2 - in your emergency situation (pH maybe 4.0), read A/B since that may abbreviate the length of time your pool spends in the pH "Death Zone".
#3 - for YOU (Service Guy), A/B testing can be a useful tool. Here's the page. (Of course, my experience is that pool service guys that come to PF -- admittedly a skewed selection -- tend to have a LOWER learning capability than the average pool owner.
#4 - for you (tinker guy who likes his pool mostly as an elaborate tinker toy), you might like using A/B.

BUT, I do not think A/B testing has value as a GENERALLY RECOMMENDED PF advice-let.

Why?

Because it's awfully easy to screw up:

"OK. I got pool water in the plastic color thingie. Check.
I put the pH bottle stuff in the side that says pH. Check.
Darn. It's a weird color.
Oh yeah. I can ADD hat A/B stuff to make it change color and then count the drops.
Ok. I add some B stuff.
Darn! No change.
2 more drops. Still no change. I'll try the other kind.
I'll add some A stuff. OK. It changed.
No, it changed back. Darn.
I'll add some more. Ok. It quit changing.
Darn! It changed back again.
Ok. It quit again. Add another drop or so.
Yeah, it stayed quit. 8 drops of A stuff or maybe 10.
Now what.
Oh, yeah. Where's that darn book.
Chart, chart, chart . . . A/B chart. There it is.
Ok, 8 drops that will be 1.28# for 5,000 gallons.
How much is my pool? Oh yea, 6,000. Ok that one.
Soda ash. What is soda ash? Wait, I don't want to increase my pH.
Darn! Wrong chart.
OK. 2.29 gallons of muriatic acid.
Sheesh. I have to use that stuff?
Wait, another chart. Dry acid. Ok
3.06# of dry acid. Ok.
I got a 5# container. That should be close enough.
Ok. Dump it in.
Crap. It's all on the bottom. Will hit hurt something.
Darn. There are bubbles coming from the plaster. That's not good.
Ok. Brush it around.
Ok. All gone; all good.
Darn. It's nearly dark. Sorry kids, no swimming tonight.
(Next morning)
Crap. What the ### is this? NOW, the fleeping pH is LOW.
Screw that stupid PF place. Off to the pool store."

And, if you think that won't happen -- pretty much exactly -- you need to answer a few more questions from Intex newbies.

But, it can be worse. If you go the other way, and add a slugged A/B dose of SODA ASH, in a pool that has moderate CA and CH . . . you've got a much better than 50:50 chance of precipitaing a calcium carbonate cloud, which is slow to clear up.

So, I guess the question is, do you want to submit a A/B testing guide we can edit and post? (And I will credit you.)

[CarlD]

Evan,
I'm willing to take your chastisement about the test kit versions. Yes, I dropped the ball on that one, though I DO like the K1000 OTO kit best.

But I'm not a pool pro, and neither are my fellow mods, as you and Ben are. I'm a shade tree mechanic as it were (as I am with my motorcycles) and I am always thinking about what is easiest and simplest for the homeowner to use to run his / her pool.

But our gradualist approach permiates ALL of our recommendations for chemical additions, whether it's acid, borax, baking soda, soda ash, or CYA. And we teach POP as part of that. We teach that POP is CRITICAL for cleaning up an algae bloom or for a Baq conversion. Yet you would have us think that applying it to an acid or base demand situation is too much and they'll run back to the "Magic in a Bottle" and get it trouble.

Well, you are not wrong. Many people will. We see it all the time when those incapable of POP have a bloom and ignore our advice (including yours) and run back to the pool store for the magic bottle. There's really nothing you or I can do about that. But does that mean we abandon the gradualist approach? Nobody likes to test two or 3 times a day. I sure don't. But when I have a problem (which usually happens when I come back from vacation or after a big storm, or days of storms) I test, add, test, add, etc.

So here's what I propose: You come up with a simplified, clear way to use acid demand that works for homeowners and I'll try it out. We can clean it up, simplify it, and make sure it's easy to use at pool side and not a white lab coat test. In other words, we can add it to the tool kit for those who want to use it as an alternate to the more gradual approach.

I don't mind having alternate approaches, though I do sometimes have to be reminded of that. But I do like alternates to be clear.

You see, I like simple, easy-to-remember approaches, preferably with a catch-phrase to help newbies and poolowners remember it. That's why I came up with "B-B-B" for Bleach, Borax, and Baking Soda. Is it complete? No. It omits acid, soda ash, polyquat and CYA. But it's catchy and easy to remember. It's a "hook" so to speak. "Ratchet down" for the TA lowering is similar to clarify the process. "Rule of Thumb" makes it easy to estimate the bleach or LC you need if you can't get to the Pool Calculator. "Shot Glass" encapsulates the method of dilution for extending OTO testing. Maybe this will be the "One-Shot" approach to raising pH. I don't know.

What I'm saying is I'm willing to work with you on it. I can't speak for the other mods or Ben, just me.

Carl

PS: I wrote this before Ben posted his last post. I should add that I will defer to Ben on modifying anything I put in this post. Still, if A/B testing is to be added to the tool box, even as an occasional test, it needs to robust and simple, not delicate and complicated, or it WILL cause more trouble than it's worth for the homeowner and non-chemist.C

[waterbear]

Ben,

I am not disagreeing with you. In fact, I agree with almost everything you wrote!

My first "response" post dealt with two issues:
1. getting the proper info to the OP about his test kit since I feel that as the 'experts' we owe that to the new members. I have seen you on many occasions ask people (including me!) to spell check before posting. IMHO, that should be extended to take a few seconds to look up some info before answering a post if you are not sure of the specifics. Being able to back up a post with facts that can be referenced only adds to the credibility of the forum.

This is what lead to the second issue, the statement that acid and base demand tests are useless. You and I do agree that, under certain situations, they can and are useful. Nowhere did I recommend them for trivial pH adjustments. I recommended them for those unusual situations where they can make solving a specific problem easier.

I think your idea of a special page on A/B testing is an excellent idea! Once again, I never said it was a test that is going to be used on a regular basis and I quite agree that getting good daily testing habits is of prime importance (just look up any of the posts I have made answering how often should a pool be tested!)

Because it's awfully easy to screw up:

"OK. I got pool water in the plastic color thingie. Check.
I put the pH bottle stuff in the side that says pH. Check.
Darn. It's a weird color.
Oh yeah. I can ADD hat A/B stuff to make it change color and then count the drops.
Ok. I add some B stuff.
Darn! No change.
2 more drops. Still no change. I'll try the other kind.
I'll add some A stuff. OK. It changed.
No, it changed back. Darn.
I'll add some more. Ok. It quit changing.
Darn! It changed back again.
Ok. It quit again. Add another drop or so.
Yeah, it stayed quit. 8 drops of A stuff or maybe 10.
Now what.
Oh, yeah. Where's that darn book.
Chart, chart, chart . . . A/B chart. There it is.
Ok, 8 drops that will be 1.28# for 5,000 gallons.
How much is my pool? Oh yea, 6,000. Ok that one.
Soda ash. What is soda ash? Wait, I don't want to increase my pH.
Darn! Wrong chart.
OK. 2.29 gallons of muriatic acid.
Sheesh. I have to use that stuff?
Wait, another chart. Dry acid. Ok
3.06# of dry acid. Ok.
I got a 5# container. That should be close enough.
Ok. Dump it in.
Crap. It's all on the bottom. Will hit hurt something.
Darn. There are bubbles coming from the plaster. That's not good.
Ok. Brush it around.
Ok. All gone; all good.
Darn. It's nearly dark. Sorry kids, no swimming tonight.
(Next morning)
Crap. What the ### is this? NOW, the fleeping pH is LOW.
Screw that stupid PF place. Off to the pool store."

As far as newbies screwing things up (if it can go wrong it will!) you are preaching to the choir! Some of the more memorable was the person who was holding the spoon part of the DPD scoop as a handle and using the handle as a scoop (all it did was waste DPD powder) and the person who was testing chlorine but the color never went "clear", it stayed a bit cloudy even though all the pink had disappeared! (Since that one I never say the color change is from red to clear but from red to colorless!)

I also used to work help desk many eons ago when I was in the software/hardware industry. (To give you an idea of how long ago we made hardware for Apple ][ and Einstein computers and software for Apple ][ and Apple CP/M and were a VAR for the ATT Unix System V PC. If you know what I am talking about then you have been using computers for over 30 years!) I think one of my most common answers (when there was nothing on the monitor) was to check if it was turned on. Most of the time it was not!
And, if you think that won't happen -- pretty much exactly -- you need to answer a few more questions from Intex newbies.
ROFL, I know you did not forget that I was a MOD at TFP for a very long time and am currently a MOD at PoolSpaForum! I spend most of my time answering newbie questions. Aldo, I used to sell Intex donuts and dealt with the new pool owners face to face! Like I said, if it can go wrong it will!
But, it can be worse. If you go the other way, and add a slugged A/B dose of SODA ASH, in a pool that has moderate CA and CH . . . you've got a much better than 50:50 chance of precipitaing a calcium carbonate cloud, which is slow to clear up.
Which is why I said substitute the Borax for the soda ash by using twice as much by weight. There needs to be CLEAR instructions for proper use of these tests, just as there are clear instructions for lowering TA (and even those are often misunderstood. I once had a long debate with someone who sells a test kit and runs a forum who was convinced that it was aeration that lowered TA even though I was trying to explain that adding acid lowers TA and aerating just brings the pH back up without bringing the TA up again also and that if you were patient enough you did not even have to aerate, the pH would rise on it's own over time but it fell on deaf ears--and this was by no means a newbie!)
So, I guess the question is, do you want to submit a A/B testing guide we can edit and post?

(And I will credit you.)

I would be glad to write something up. Should I email it to you or just post it? I probably won't have the time until next weekend, however. I am not looking for credit. No reason to add the quote bracket! If you want to give me credit fine but that is not my motive!

[PoolDoc]

Yeah, mail it to me.

No hurry --- I'm shifting to winter mode, so we can bang it back and forth a few times before opening it up to others.

Ben