Copper in test tubes

[JTrigger]

Probably a stupid question, but if I were to use test tubes from a standard master kit to measure NH3/NO3/NO2 in my QT (with copper), do I need to soak the tubes in vinegar overnight or just rinse with tap water? I won't be dunking the tubes in my display or sump so would rinsing be adequate? I think I'm just getting paranoid... lol.

 

[JHemdal]

The amount of copper that could possibly be adhering to the test tube is of no real consequence. However, some test kit chemicals (specifically the cadmium reduction nitrate test) are very toxic to people (and probably fish/coral). Always a good idea to rinse the tubes out with distilled water after use, use a clean cup or turkey baster to fill them, and keep all test kits away from children.

Jay

 

[Chris27]

Just rinse them out after use and you'll be fine. Filling the test tubes with a syringe is much easier anyhow, one could go mad trying to measure out 5mL by scooping water from the display.