Re: 10% water change Prime dosage?
Glad to hear that you are switching completely to Prime:) You will only need to dose Prime for the amount of water that you are replacing. Because Prime is so concentrated, you will only need a very small amount for your 2L replacement water.
The instructions say to use 1 cap (5mL) of Prime per 200L of water. Since you will only be dosing for 2L of water, you will only need 0.05mL of Prime. Therefore, 1 drop will be sufficient for your 2L bucket. Just FYI, 20 drops is approximately equal to 1mL. Hope this helps!