Testing for high FC with basic test Kit

[mh0520]

I have a TF100 test kit and as I understand the best method for testing for FC is the FAS-DPD method. That being said it seems like the recommended method for daily testing, unless you're doing a SLAM, is to use the basic tests kit with the OTO drops. If you need to maintain high levels of FC because your CYA is higher, I'm thinking in the 6 or 7 range, is there a workaround for using the basic kit. For instance, can you dilute the pool water 50/50 with either tap or distilled water, and then just multiply the result that you measure by 2?

 

[mknauss]

To be honest, in 6 years, I have never used the OTO kit for a daily test. I have used it when I got a weird FAS-DPD result. As the OTO will definitively tell you if you do or don't have chlorine in the water.

 

[Donldson]

The OTO test isn't even all that accurate even within the range it can test for. It's a simple "yep, same color as yesterday" test.

If you want exact, just use the FAS-DPD test.

 

[mh0520]

Thanks, I was assuming the answer was to just use the FAS-DPD test but I figured I would ask.

 

[pb4uswim]

To be honest, in 6 years, I have never used the OTO kit for a daily test. I have used it when I got a weird FAS-DPD result. As the OTO will definitively tell you if you do or don't have chlorine in the water.

So what do you do to keep an eye on the PH?

I ended up getting a digital PH tester. I use that and the FAS-DPD test from my TF-100 for FC on a regular basis. I do use the OTO kit but as described, not much help on the FC. It does however, coincide with my digital tester for PH. If they ever don't coincide, I'll recalibrate my tester.

 

[JJ_Tex]

Dang, I must be in the minority but I like the OTO for my daily testing. My target FC is 5 and a quick 5 drops and I can tell how I'm doing in under 30 seconds. Add another 1 min to check the skimmer, and I'm done with my pool maintenance for the day.

I do the DPD as part of the full weekly test, but not daily.

 

[mknauss]

So what do you do to keep an eye on the PH?

I use the pH test. The OTO is the TC test. The yellow comparator.

 

[tim5055]

I do not recomend this method, but I have a friend that just lets a couple of drops from the OTO go in his pool. If he sees yellow, it's yes, I have chlorine. That is about the same specificity you get in the tube. Yes, I have chlorine. You never know how much, but you have some.....

 

[duraleigh]

Dang, I must be in the minority but I like the OTO for my daily testing

That was the way I did it for 10+ years. Easy Peasy

 

[pb4uswim]

I use the pH test. The OTO is the TC test. The yellow comparator.

Got it. I thought OTO was just a way to abbreviate the basic double test kit. Thanks.

 

[mh0520]

I use the pH test. The OTO is the TC test. The yellow comparator.

Okay, I feel a little stupid now. I just realized that the OTO in the test basic test kit is TC and not FC.

 

[mknauss]

Got it. I thought OTO was just a way to abbreviate the basic double test kit. Thanks.

OTO (Orthotolidine) Test

OTO is a solution that turns yellow when added to chlorinated water. The darker it turns, the more chlorine is in the water. If the chlorine level is really high, then the sample will turn brown.