Elos KH test kit

[asylumdown]

definitely, when I was counting drops I had to re-do my tests half the time because air bubbles would get in to the fluid and you'd end up dispensing some weird fraction of a normal drop. Wasted a lot of reagent that way, especially when you were near the end of the bottle.

Plus each drop can be a different size depending on how steady your hand is, so one result might give you a way higher result and another test 5 seconds later might give you a totally different result.