The length of a cycle will depend on which mode you’ve selected. Eco-Express runs 3-5 hrs, Lomi Approved runs 5-8 hrs, and Grow mode runs 16-20 hrs. In all the modes, cycle length does vary based on the type and quantity of waste you’ve added.
If a cycle is running significantly longer than you'd expect, there's a chance your Lomi is actually on the Grow or Lomi Approved mode. The light indicating which mode you're on will shine brightest underneath the mode it's running.