Eliminate Debris

• Most water filters contain charcoal, which is a brittle material that is made by burning wood in the absence of oxygen. When your water filter was packed, all of the pieces of charcoal were large enough not to pass through the final screen and wind up in your drinking glass. The process of shipment, however, may have ground some pieces small enough to pass through that screen. Running your water for 10 minutes after first installing can help ensure that any of those small bits of debris are passed through into the drain and not into your glass.
  
  

Settle Filter Material

• In shipment, filter material such as charcoal can become unsettled and unevenly distributed across the bottom of your filter, which can leave gaps between the filtration material for water to pass through without being properly filtered. Running your water for 10 minutes can help ensure the filtration media has settled to the bottom of the filter and is acting as a sieve, with all water having to pass through the media before coming out of the filter and ending in your glass.
  
  

Ensure Filter Integrity

• Likewise, shipment may have cracked or broken part of your filter. Running it for 10 minutes can help you identify any flaws or defects in the filter before you drink water that has emerged from it. Any leaks or filter failures should be immediately evident, and you can disassemble and return your filter to the manufacturer or place of purchase for a warrantied replacement. Better your filter fails immediately and harmlessly into the drain than breaking apart into a pot of spaghetti.
  
  

Activate Filter Media

• The filtration media being used in the particular filter you have purchased may be inactive until it has been wet, which means the first batch of water that passes through the filter has not been filtered and may in fact be contaminated with whatever sealing agent was put on the media to prevent it from caking together in the presence of humidity.