I picked up a new drop checker from Dennerle – the Carbo Test Precision, sold by Real Aquatics. This drop checker comes in three different sizes. I got the small 20 mm version which actually surprised me by how small it turned out to be. This checker is different because instead of having a hanging tear-drop shape, this one is spherical and has a white plastic tube embedded in the middle providing an opening to the bottom. The idea here is that the drop checker solution can easily be viewed against the white background of the filling tube which provides a more consistent reading than all-glass checkers where you’re always looking at the colour of the solution against a background of something else.