New to testing, question about the stain warning included with the FAS-DPD test


Dec 10, 2020
Addison, TX
Hi, I just ordered my first test kit and I'm attempting to learn how to test my water in preparation for owning a pool. I saw this warning in the test kit:

We have two cylinders in the test kit because one should be used for Chlorine testing only. This is because the nature of the R-0870 powder is to stain EVERYTHING (don't spill it). It will stain cylinders, the blue spoon, etc. You can clean them off with rubbing alcohol. Just remember to rinse well after you clean them. You can buy replacements for these at under "kit hardware".

When it comes to staining everything, is this only before it is mixed with the water or should I watch out when pouring the solution down the sink after testing? Will I need to also clean the sink with rubbing alcohol? I also bought the speedstir and I was curious about the little magnetic magnet. Should I get a second magnet so I can use the speedstir for both the chlorine testing and the other tests or is that unnecessary?

I haven't tried testing yet so I don't have any experience with this.


Silver Supporter
May 12, 2020
I have been using the FAS-DPD test with the speedstir for a month or two now, I don't see any staining on anything besides the little blue spoon. The tube is still clear, and the bean is still white. I don't think I have spilled any or at least I haven't noticed any odd stains? When I have poured it down the sink, I always have the water running so it flushes it down quickly.
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Bronze Supporter
Jun 1, 2018
Hernando, Ms
Pool Size
Salt Water Generator
SWG Type
Intex Krystal Clear
If the sample is allowed to sit in the test vial for an extended period some staining can occur but most people rinse everything fairly quickly after testing is complete so its a moot point. I do try to keep the powder & spoon in the same little compartment since over time loose powder can discolor the plastic. Especially since I don’t always rinse & wipe my spoon.


Gold Supporter
Bronze Supporter
Jul 17, 2019
Prosper, TX (DFW)
Pool Size
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
After a year, my vial, spoon and bean are stained. Not horrible or impactful to the test, but I can easily pick out the chlorine vial and bean when they are next to the other beans and vials in my kit.

If it was impactful, I would try and clean it with alcohol... but its not, so I just leave it be. I do not think it is anything to be overly worried about I have also not noticed any staining on my table if I have spilled anything nor in the grass/flower beds where I dump the vials after use.
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