R-0870 powder leaving residue in my cup

[Mtpisgah]

The R-0870 powder leaving residue in my sample cup, it sticks to the sides and does not come off easily. It has been doing it for a while and I dealt with it but I just bought a speed stir and I want to keep it in good condition. Is this typical? It expired three months ago and I have some on order, but was doing it before that too.

The pool is looking crystal clear thanks to TFP.

 

[mknauss]

Are saying in your test vial? Clean it with bleach or rubbing alcohol. Either should clean up the test vial.

 

[Mtpisgah]

Yes, the test vial. I can get it clean, but is it normal? I do not remember it doing it when I first bought it.

 

[mknauss]

It is normal.

 

[Mtpisgah]

Ok, thank you.

 

[Smehltrett]

I use a vial for chlorine only as it's always stained from the powder