Cleaning the FAS-DPD scoop

Foonly

Active member
May 24, 2018
44
St Augustine FL
I have a Taylor K-2006 test kit which includes the FAS-DPD test with the tube of powder R-0870 and a tiny spoon for measuring it. I am on my second such tube of powder. I notice that the little sccop never really empties even though I tap it over the comparator tube. After a while whatever is left in there turns black. I worry that I am not getting the proper amounts or that this black stuff contaminates the result or the unused powder. Between tests everything goes back in the plastic box which is stored inside the house in a cool dark place. What is the proper technique for handling the scoop and cleaning it?

When I put in the called for two scoops, I use "level" sccops as one would use when baking.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
20,376
Laughlin, NV
You can use rubbing alcohol. Should clean it up.

For FC testing, use a 10 ml sample, one scoop, and each drop of reagent to clear is 0.5 ppm FC
 
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Wobblerlorri

Bronze Supporter
Marty is right, regular rubbing alcohol will clean it off. In the future, wipe the scoop off with a clean paper towel to remove the excess powder. And tap it on the vial like you mean it! Don't be gentle, neither the vial nor the scoop is going to break.
 
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Wobblerlorri

Bronze Supporter
If one scoop of indicator powder makes your sample turn pink, then it's enough. All it's doing is indicating there is free chlorine in your sample. You can add two scoops of you want, but all that will happen is your sample might turn pinker.

And those scoops are level, as in tap the side of the scoop against the bottle to knock off the excess. No need to be ultra precise.
 

rowiac

Active member
Apr 20, 2018
44
Tehama County, CA
I believe the TF-100 kit says to use a single heaping scoop. That's what I do, just making sure the powder is mounded up a bit and dump it in. I think that two scoops, level or not, would be a waste.
 

HeyEng

Silver Supporter
Nov 7, 2018
341
Oklahoma City, OK
The instructions say two scoops regardless of which sensitivity you use. I use the 10mL level anyway so if one scoop is enough I'll do that.
I have tried different amounts (two level scoops, one heaping scoop, one level scoop) and the FC level came to within .5 PPM no matter how much I used. As mentioned, as long as the sample turns pink, there is enough in there.

I rinse out the scoop (tap water) when I am done and let it drip dry.

The instructions say two scoops regardless of which sensitivity you use. I use the 10mL level anyway so if one scoop is enough I'll do that.
The Taylor folks would *love* for you to use two scoops. They get to sell more product that way. :)
 

LoneWolfArcher

Well-known member
May 29, 2019
222
Michigan
I have tried different amounts (two level scoops, one heaping scoop, one level scoop) and the FC level came to within .5 PPM no matter how much I used. As mentioned, as long as the sample turns pink, there is enough in there.

I rinse out the scoop (tap water) when I am done and let it drip dry.



The Taylor folks would *love* for you to use two scoops. They get to sell more product that way. :)
While maybe true......I am no longer skimping on testing! That is how I got in my mess to begin with. :)
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
42,993
Tucson, AZ
The way i know i added enough is after the test, add tap water, if it turns pink again, then there was enough powder to react to FC.
This is not going to work for many people that have no chlorine in their tap water and I am not sure I see the value of it.
 

anthony21078

Well-known member
Jun 14, 2018
68
Long Island NY
While we are on while we are on the topic of discoloration, I noticed that my one month old Taylor CYA vile has a purple ring at the bottom. What's the cause of that?
 

Wobblerlorri

Bronze Supporter
While we are on while we are on the topic of discoloration, I noticed that my one month old Taylor CYA vile has a purple ring at the bottom. What's the cause of that?
Are you rinsing out your vials with plain tap water after every use? And not just gently rinsing -- blast that water in there! You need to thoroughly rinse all your vials vigorously with plain tap water after use. In fact, best practices for water labs has you rinsing the labware with the sample water before use, too. But we don't need to be that precise.

You can put some warm water with a drop of dishwashing detergent in your vial, then let it sit and soak for an hour or two. Then scrub it out with some paper toweling wrapped around your little finger. Rinse, rinse, rinse. The vial will have a definite sparkle when it's clean.

If that doesn't work, you'll need a new vial.