The following response applies to all models in the Berkey® range, with adjustments for volume calculations.

The volume of each model refers to the volume of the lower tank. This means you can have up to 8.5 liters of filtered water in stock.

Explanation: The upper tank is slightly less voluminous for safety reasons to prevent overflow if the lower tank is not completely empty.

To be more precise, for the Big Berkey, the top tank has a volume of 8.32 liters. Additionally, the volume of the Black Berkey® filters must be taken into consideration. Each filter has a volume of 0.51 liters.

If your Big Berkey is fitted with 2 filters, you can fill a maximum of 7.3 liters of water.

You will actually fill slightly less than this because there is always about 2 cm of water remaining at the bottom of the tank (see explanation here).

Also, when you have emptied the lower tank, roughly 1 liter of water will still left in the bottom of the tank (see the previous link).

The amount of water you can put in the upper tank has been carefully designed and determined by the manufacturer to allow, in regular use, a volume of 8.5 liters of filtered water in the lower tank, whilst preventing a risk of overflow.

Tip: If you would like to completely empty the bottom tank into a jug, this can be done by tilting your Berkey® forward gripping the knob on the lid.