test tubes

[angelofdeath132]

how does everyone clean out their test tubes(vials) for their water tests? mine are getting "cloudy" (for lack of a better word)
from testing all the time, and i'm afraid this is not gonna give me a correct reading. can i boil them in water for a few minutes?

 

[splash1914]

go with the test strips....

 

[aqua blue]

I know that you can clean hydrometers with a vinegar and water mixture. I am not sure about test tubes. I e-mailed Aquarium Pharmaceuticals and asked them them the same question. If they answer me I will let you know.