4 dKH Reference Solution

Make your CO2 dropper checker work like its supposed to. Your drop checker is only as accurate as the reference solution used; calibrated 4 dKH solution will make your drop checker as accurate as you need it to be. Many drop checker's instructions call for using tank or tap water, basically making the color reference useless since the pH solution used is meant to be used with calibrated 4 dKH solution.

Each batch is triple tested to ensure accuracy. 4oz bottles last a long time and the flip top cap makes it easy to fill your drop checker.