OTO vs FAS/DPD

Sammy2

Well-known member
Aug 30, 2016
378
Riverside, CA
#1
As I understand it if you're using FAS/DPD to test for FC you don't need OTO to test for TC. Did I miss something here? The reason I am asking is that I'm considering getting the Taylor 2006C test kit but it doesn't have the test for OTO included and I'm not sure it is really necessary if I'm testing for FAS/DPD and salt concentration with a K-1766 test kit.

TIA

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Let me add that our water is pretty hard here looking at the differences I see the TFT kit has more tests for CYA and less for hardness and TA. I think 8 tests for CYA should last me a year, maybe two.
 

pooldv

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Aug 10, 2012
24,993
DFW, TX
#2
Here is a handy comparison chart. Pool School - Test Kits Compared

Yes, no need for OTO if using FAS-DPD. OTO isn't very precise and only reads to 5, although you can estimate deeper shades of yellow/brown/orange that it turns. Most folks use it as a quick test to make sure FC isn't 0.
 

Sammy2

Well-known member
Aug 30, 2016
378
Riverside, CA
#3
Here is a handy comparison chart. Pool School - Test Kits Compared

Yes, no need for OTO if using FAS-DPD. OTO isn't very precise and only reads to 5, although you can estimate deeper shades of yellow/brown/orange that it turns. Most folks use it as a quick test to make sure FC isn't 0.
That's the chart I was using. I sorta kinda want it here by this weekend so shipping from SC is a huge cost. If I go amazon smile TFP still gets a little money and I get my kit here sooner. I'll do that so that I have it here and get more TA and Hardness tests.

BTW, I'm calling my pool guy today and dismissing him. There's no reason to keep bleeding $105 a month on "pool maintenance", especially when something "hard" needs to be done I end up paying extra.
 

JoyfulNoise

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Platinum Supporter
May 23, 2015
14,514
Tucson, AZ
#5
A K-2006C is a good kit. You don't need OTO and it comes with both acid demand and base demand reagents which is a nice way to figure out how to raise or lower pH without having to know TA or any other water parameters. I personally find the acid demand drops useful for doing quick pH adjustments without having to fire up the diesel-generator powered laptop to bring up PoolMath...

If you wanted a quick "spot test" for FC and pH, then you could also purchase a Taylor K-1001 which gives you a DPD-only test (pink color comparator block). I also have one of those and often do quick chlorine testing with that instead of whipping out the SpeedStir and the DPD powder.

I say this a lot, but in my opinion, OTO is not very useful at all given that it measures TC and it is often wildly far off in color from the actual chlorine concentration. The fact that many state Health Department use it as their "definitive test" for determining water safety is down-right scary in my opinion....
 

Sammy2

Well-known member
Aug 30, 2016
378
Riverside, CA
#6
You can order the TF-100 from Pool Supply World and they'll ship from cali.

Water Testing - TFTestkit TF-100 Seven Test Kit - TF-100
This I did not know. I was going off of the "About Us" page. That's a whole different dynamic then. How do you know this (other than being a Mod!?)?

That said, what about testing for hardness and TA?

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I got a cool code for $10 off when signing up but the TFT-100 and Salt test from TFT is $100 less $10 but the shipping is $18.40. I suppose I need to pick something else, maybe a hardness test kit!
 

pooldv

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#7
I also have the DPD chlorine test and I use the larger comparator block that reads to 10ppm. But, I have trouble reading the shades of pink/red except in very bright light. Which is apparently a fairly common defect in men. That probably also explains why we have so much trouble picking out the right shade of lipstick. :-D
 

Sammy2

Well-known member
Aug 30, 2016
378
Riverside, CA
#8
I see, that order is from another etailer. I bought replacement hoses for my Kreepy Krawler from them last year for $1.99 each on clearance.. or pricing error.
 

pooldv

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DFW, TX
#11
TF-100 has CH and TA tests. Good to go.

I don't know why I know that other than reading lots of posts. Or Mod super powers. :)
 

Sammy2

Well-known member
Aug 30, 2016
378
Riverside, CA
#12
Actually, since I ordered from Pool Supply World before, I had it in an email from just a day or so ago. I called. No guaranty of which of many warehouses it would ship from and they cannot tell me where it is currently stocked. Hmm.. I really want to get a handle on my chemistry this weekend!

I suppose I am not being as clear as I could be and was confusing myself. It is that the Taylor 2006C has more hardness tests than the TF-100 kit.. I think I'll order from amazon and get it here by Friday as I don't really see a need for the OTO test
 

Sammy2

Well-known member
Aug 30, 2016
378
Riverside, CA
#13
Couldn't pass up the price and I had a $10 off $100 coupon that I got for entering a different email address. To get to $100 I added a leaf rake (ours broke a while ago but didn't need it if I had a guy doing it, but now I need one) and a ducky thermometer as our fishy thermometer is no longer purple but a faded shade of blue. It will not be the end of the world if I cannot test it until a week from now so why pay more?
 

pooldv

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#14
Good news! I always heard that the ducky thermometer is more accurate than the fishy thermometer. :thumleft:
 

jmastron

LifeTime Supporter
Jul 21, 2014
254
Sacramento, CA
#16
I also have the DPD chlorine test and I use the larger comparator block that reads to 10ppm. But, I have trouble reading the shades of pink/red except in very bright light. Which is apparently a fairly common defect in men. That probably also explains why we have so much trouble picking out the right shade of lipstick. :-D
To solve that I installed an app on my phone that just displays a bright white screen and I hold that behind the comparator; I find it a lot easier and more consistent to read both the DPD FC and the pH that way. I also use the FAS-DPD test occasionally to check and calibrate my eyes. I'm a bit red/green color blind, and I'm impressed that I'm able to get the DPD reading within 0.5ppm of the FAS-DPD reading usually.