Taylor chlorine comparator

[JoyfulNoise]

Glad to hear it worked out. Taylor changed their bottle labeling recently. Reagents with a lot number only were manufactured PRIOR to 2015 so those reagents could have been 2+ years old. The DPD reagent (R-0002) is definitely susceptible to aging where the dye molecule will slowly oxidize over time to form an imine molecule which is a clear compound. Taylor puts additives into the R-0002 to stabilize the chemistry as much as possible but it's not perfect. This is why you should always keep your reagents tightly capped and stored in a cool, dry environment.

My guess is, if you purchase the titrating reagent, you'll find the "squeeze" of the bottles to be a little different and so you'll probably see some variation in droplet count (minor) due to that. I would simply suggest you pick one bottle type you like and stick to it or else you'll run yourself in circles with testing. Developing consistency in your testing skills is the most important thing.

Thanks for bringing this up. It's a very good object lesson in testing and reagent shelf-life.

 

[joshua5438]

WOW.. Thanks for all the info! I have not ordered that block but this makes me feel confident about getting it.

 

[mikemass]

WOW.. Thanks for all the info! I have not ordered that block but this makes me feel confident about getting it.

Funny that it was you that started this thread. Sorry I kind of "took over" the discussion. But your initial question prompted me to be the guinea pig and buy the 2000 series comparator. And they my experience just took on a life of it's own. But getting back to where this thread started:

Yes, it's an excellent comparator. Way more professional than the one in the Taylor "Basic Kit". Some advantages:
Cl goes up to 10 ppm vs 5 ppm
Cl reading uses pinks, rather than canary yellow which gets hard to read at higher levels
Has dilution marks on both the Cl and pH tube
Cl tube doubles as your CYA test tube (has black dot on bottom)
pH tube doubles as your TA and CH tube. (has all kinds of ml markings on it)
Black rubber cap fits nice and tight

 

[JoyfulNoise]

Just so you're all aware of the pros & cons, DPD is not perfect. For instance, the color intensity changes linearly (mostly) from 0 to 5ppm and then very non-linearly from 5ppm to 10ppm. This why the color swatches go from 5 to 7.5 to 10ppm. Many people find the darker shades of red-pink harder to distinguish. Also, DPD suffers from bleach-out when the FC is over 10ppm. If your FC is higher than 10ppm, the test can actually show a lighter pink color. And, as seen, DPD has a limited shelf life. OTO, by comparison, can show higher levels of total chlorine, does not bleach out until levels are very high and is a very stable dye that can last for years. OTO is also a lot cheaper than DPD.

Given that info, the pool owner should choose a test that best works for them. I prefer the DPD only test over OTO but that's just me. Others prefer no instant test at all and like to do titrations for their daily testing routine. It's all a matter of finding the testing regimen that works best for them.