Here is my diy drop checker. I figured that since it contains quite a bit of air and solution, and the surface area of water to air isn't much, it will take a while to come to equilibrium with the water. How much of a delay do you think I can expect between changes in the water and changes in the drop checker? Also since it's closer to the surface, would it actually probably read low compared to if I had it half way to the bottom of the tank? The whole thing is about a cup. I considered trying to put something inside it to reduce the volume of air but couldn't really figure out what to put in.