OTO or DPD for daily tests?

[marcgr]

I have a TFT-100 and within that came a Taylor K-1000 (OTO-based) basic test kit for the daily tests.

When I ran out of reagents for the K-1000, I tacked one on to an order I had from another pool supply house (as I was already into free shipping) and they sent a K-1001 which is a DPD version of the K-1000.

Just curious why the TFT-100 has an OTO rather than DPD for the daily tests? Any advantage to using one over the other?

Thanks,

Marc

 

[Texas Splash]

Hi Marc. Just to prevent re-inventing the wheel here, you might like THIS THREAD. Might clear it up for you. If not, let us know if you still have questions.

 

[pooldv]

I use all three. I have the DPD comparator that reads to 10ppm, which is handy since I always maintain more than 5ppm FC. It is a little harder to read the pinks sometimes. And it is pretty easy to calibrate your eye to read the brighter shades of yellow that the OTO test gives you at readings higher than 5 ppm,as Richard says, tweety bird yellow, school bus yellow, etc. I wish they made comparator for OTO that went to 10 ppm. Of course, it would be even better if it went to 11! :-D Maybe I should try my DPD comparator and see how it works.

 

[JoyfulNoise]

I prefer the DPD test because it is a true FC test as opposed to OTO which total chlorine.

 

[duraleigh]

Just curious why the TFT-100 has an OTO rather than DPD for the daily tests?

The DPD is a poor choice. It only measures to 10 ppm so why not go with the FAS/DPD and get precision at high levels as well......one is as easy as the other.

The OTO, on the other hand, is included because it is FAST, reliable, and inexpensive. Use it to test for the presence of chlorine, not a precise ppm. Use the FAS/DPD when you want to know the precise number.

I have users tell me they never use anything but the FAS/DPD because they like the precision. I have other users that know their pools so well they can use the OTO over and over unless they suspect a deviation, then they use the FAS/DPD.

OTO and FAS/DPD gives you the best of both worlds......DPD gives you neither.