Congratulations! This indicates your Black Berkey filters have been perfectly primed!
The water gently trrickles through as soon as you fill the upper chamber. It is the weight of the water column that forcefully pushes the water through the filters. Once the water column decreases (between the last third and the halfway point), the water drips quickly.
What makes the Black Berkey filters strong and efficient are the microchannels that take a tortuous path, allowing the water to contact the filter over a long distance. But since there are millions of these microchannels, in the end the water filtered very quickly.
Generally, a full chamber is filtered in 45 minutes, give or take 10 minutes. If this is not the case, it means your filters are not properly primed. You should then re-prime them according to the instructions provided in your manual.
If you find that the filtration is very fast (10 to 20 minutes), again, don’t worry! The filtration speed indicated by the manufacturer is an average, and very fast filtration does not indicate that your filters are not working. First, check that your black seals are properly installed in the upper chamber and that the blocking plugs are securely in place and tight (except for the Travel model). Also, make sure the wing nuts are sufficiently tightened (without over-tightening). After that, when the water is being filtered, check by lifting the upper chamber that the water flows only through the ends of the Black Berkey filter stems. Finally, if after all these checks the filtration is still very fast, you can perform a red dye test following the instructions in your manuals or in our FAQ. This is the final step that will find out if your filters are working properly or not.