Acid and Base Demand tests: Useful or Not?

[PoolDoc]

Guys, I think you're losing track of the OP. Carl, Waterbear . . . if you want to discuss the relative merits of using or ignoring the acid / base demand test, please open a new thread in the China Shop. Personally, I always ignored it, because I have long preferred the little dose, retest and add another little dose approach. But, I never had to work with residential pools that had been mega-over-dosed with acid or soda ash.

Still . . . China Shop, please.

Thanks,

Ben

[waterbear]

China shop is fine with me. Carl, care to split the thread? Post 9 seems to be the place where it went south.
And to answer your question, acid demand test is VERY useful when lowering TA.
Only time I ever had to use a base demand is when someone was not paying attention to their pool chemistry and was using trichlor and had a pH/TA crash and that is rare but I do use the acid demand test all the time.

[CarlD]

Evan,
I'm always open to new ideas. Tell me how to use the acid demand test (I mean, other than directions) and what I can hope to learn from it. Is it REALLY that needed beyond a gradualist approach?

Carl

[PoolDoc]

Evan;

My take on AD & BD tests is that they can provide information someone might LIKE to have, but --- major overdose correction situations aside --- there are few (if any) cases where they provide information someone NEEDS to have.

For example, if you want to lower alkalinity, an AD test will be able to help you estimate how hard that's going to be. But, from a PF 'answer' point of view, what rookie pool users need to be told is STILL "hold your pH to 7.0 or just below until your TA drops to an acceptable level". Functionally, they need to do it however long that takes, and knowing that it might be a long time, doesn't modify the process.

So, as I see it, the AD test adds (to use an awful neologism) "non-actionable" information. You 'know' more, but you can't DO anything with that knowledge.

Granted, it might help with some of the 'Nervous Nellies' or OCD types that show up here. But my experience is, in dealing with OCD's that there is NOT a level of information that actually relieves their itch. No matter how much you tell them, they still want more.

However, if you tell them too much that's not "actionable", this new (and functionally useless) information confuses them or distracts them from paying attention to the USEFUL information, like how low their FC level is.

Anyhow, that's my opinion. But, I'm open to correction.

Ben

[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.

[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.)