I know OTO isn't recommended for the advanced testing required here on TFP to assess and troubleshoot your pool. But I do know many here recommend it for at least day/day CL dosing. Which is exactly what I'm doing.
*see my sig, TF100 soon.
In the interim, I have been using OTO to check & dose with 6% fresh bleach.
I have discovered that it has been lying to me, can it do that even if the re-agents are fresh?
>>>>Here's my testing procedure<<<<<
- I rinse it after every use /w tap water, leaving it sit open indoors in a cupboard /w the caps off, also rinsed.
- Before each use I swish it around really good in the pool and fill the vials, then shake them up, dump & rinse once more.
* Probably excessive, but I want to be sure it's clean.
** The sample tube plastic never gets cloudy.
- I then invert, go down about a foot next to the AGP Intex skimmer basket "intake", then upright the vial and remove, tapping out the water to the line.
* Doing it by the return is about the same result.
- I add my drops, wiping the tip 1st on my arm, even not wiping it doesn't change it.
* It also doesn't really matter how many drops or how small a sample size I use, it's all the same, finite difference when there is one.
- I check the sample as soon as I invert, sometimes it goes a bit darker after about 3sec. or so, sometimes it doesn't, so TC the same and if I let it sit for 2-3min for the true TC reading, sometimes it's actually lighter. HUH? Bleaching? Why?
* If the sample sits in the tube /w the cap on, inside it's cabinet for several hours or overnight, it goes completely clear. I assume that's normal?
<<<<<<Here's what's happening>>>>>
So today I checked it about 2pm, got a very light yellow, like ice melted, diluted lemonade left in the bottom of a glass.
So it's 0.6ppm.
*Yes, low, I know, but you'll see why in a sec.
So I added 30oz of bleach about 5:00pm to bring it up by 4.3ppm for a total of 5ppm FC. This way I should get a dark yellow, no chance of orange as it's nowhere near that.
Well, so I thought. I tested it at 7pm, about 2hrs later.
What do I get? A medium orange, like a Jolly-Rancher orange. It's not dark yellow /w a tint of orange, it's clearly orange.
According to this link, that's probably about 15-20ppm.
FC was low this afternoon because I have been seeing that it lies to me. I got about 5ppm yesterday before sundown, out in sunlight. Last night I got a reading of say about 1.0ppm in artificial light. Knowing that makes some difference, I just went with what I tested in the daylight & knocked off 1ppm to accommodate for a little extra FC loss. So I dosed it based on 4ppm. So 2cups of bleach.
Sometimes this works out, sometimes it doesn't, but it seems to be better overall than really believing the test at night. Otherwise if I really believe what it tells me, I get a nice orange color, waiting 30min to an hour before testing.
Is that enough time with my Intex pump for it to mix up?
So I'm a bit lost, I know OTO isn't terribly accurate and a lot of people have problems judging the different shades of medium to darker yellows. But the low, light yellows are EASY!!
It's even failing on that.
Advice, suggestions would be GREAT!!