The Laterals on any sand filter are the 8-10 plastic tube at the bottom of most sand filters. The Laterals act as sieves to keep the sand from entering the pool water as it is filtered through the sand. See our guide on "How a Multiport Valve Operates" for more information on Laterals work. If you are getting sand in your pool or your filter is not filtering as well as it did, it may be time to remove your filter's sand and look at your filter's Laterals to see if they are damaged. This guide shows you where the Laterals in your Pentair Triton 2 Side Valve Sand Filter are, and how to check and replace them.