Ten years ago, 3/16” diameter tubing was introduced to the marketplace as an alternative tubing to 5/16” diameter tubing. However, recent research shows that sap production in 3/16” tubing drops off as soon as the second year after installation due to microbial growth. A replacement for 3/16” diameter tubing in gravity systems could be 1/4” tubing. With almost twice the aperture of 3/16” tubing (0.049 sq inches compared to 0.0275 sq inches), 1/4″ inch tubing is less likely to plug from microbes yet is still able to create a full column of sap for gravity vacuum. Quarter-inch tubing is currently not available for maple producers but can be procured from other industries and, with modifications, will work for maple production.