Hanna checker lab glass cleaning

[pelicansreef]

What do you guys use to clean the Hanna checker vials for the nitrate tester or Phos checker? After a few dozen test the glass doesn't seem to come as clean as when they are new. I'm know Hanna sells a cleaning fluid but I'm looking for a cheap hack if you have one that works

 

[homer1475]

Store them full of water, and use a microfiber cloth to clean them. My Alk tester is 2 years old now, the glass still looks brand new

 

[paul01609]

Same keep the filled with RO water

 

[pelicansreef]

I will give that a shot. I usually rinse them and use a paper towel to dry the inside. I always use a micro cloth for the outside to make sure there are no finger prints