TFTestkits has a big "Oops" to report

Here is the correct way to use dropper tips on all the tests.

1. The bottle should be held vertically...not sideways or somewhat sideways but vertically I'll get to why in just a second.

2. Importantly, the drops must be dispensed slowly...roughly one drop every second or two.

3. Here's the biggest thing to remember. "Squirt" should never be in your vocabulary. The drops must fall off the tip. If you are forcing them off, you are going too fast. A slow, steady pressure is all that's required.

That's why you hold the bottle vertically. the drop is formed on the curvature of the tip and is held on the tip by surface tension. As the drop gets bigger, finally gravity wins and the drop falls from the tip. If you don't know how to do this or can't do this, you will never get accurate test results.

Interestingly, the size of the hole or the hole being "off" has virtually nothing to do with the drop size. The curvature of the tip could affect the size somewhat but, even then, I took a tip and partially melted it so the tip was pretty badly misshapen. Despite that, I still got a decent drop.


On a slightly different note, there is a known variation that must be taken into account when you do the TA test. There is something inherent in the R-0009 reagent that causes it to develop a static charge when the reagent is very fresh. Because of that charge, the R-0009 reagent Actually "jumps" off the dropper tip before the drop is fully formed. the resultant smaller drops will give you a false high reading.

The solution is simple but a bit tedious. Simply wipe the dropper tip with a damp cloth or paper towel in between each drop. That dissipates the static and the drop forms correctly on the tip. That phenomenon last 2-3 weeks on a new kit and I do not recall seeing it reported much after that.

To the best of my knowledge, that only occurs on the R-0009 so don't apply that to any of the other reagents.

I know this is a hi-jack but there is so much misunderstanding about how to perform these drops based tests I felt it was timely.
 
Just saw this post, wish I had seen it a week ago. Was having a devil of a time getting consistent drops, was the hardest part of the entire process. Was beginning to think I was incompetent, as my FC tests would be wildly inconsistent. Have one good tip, will put it on the 0871 and see if things get easier and more consistent with FC at least. Email sent, waiting on the replacement tips. Thanks.
 
New droppers for TF-100 kit refills?

Hi - I recently replenished the R-0010 and R-0012 reagents in my TF-100 kit. These are for the calcium hardness test. I did not replenish the R-0011 this season since you use so little of it per test (3 drops) and I still have plenty left...perhaps I should have replaced it...but I'll bring up my concern anyway.

As soon as I started using the new reagent my test values for CH have doubled. I had been running at 500ppm (with the older, and now empty, reagent) and now the test shows just shy of 1000ppm.

It's my opinion, but the drops coming out of the R-0012 reagent appear smaller than the previous bottle (needing more drops per test explains the higher value). The drop stream is also much more difficult to control; it can squirt out too fast rather than drip if just turned upside-down (if that makes any sense).
I've also had a similar issue with my new R-0009 (alkalinity reagent) where the dropper is quite eager to dispense with the slightest pressure...

I think my tests might have been compromised with different sized drops. Has anyone encountered sometime like this on new bottles of reagent? Has something changed with the bottles?

Sure would appreciate any of your insight. Thanks.
 
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