This is my first post on TFP. I have a two year old pool and sand filter. It is a Waterway Millenium 22". When my installers first came out I only noticed them adding one 50 pound bag of sand. I figured maybe I just missed them adding the other bags of sand. I have had filtration issues the last two summers. Over this past weekend I decided to open up the filer and verify my sand level. I only had 6 inches of sand . After adding two 50 pound bags it brought it to about 9-10 inches from the top. My question is with just the 6 inches of sand I am sure that my 2 stage 1.5HP pump was flowing really well. Could that have caused me to get some sand in my pool from the returns? I know normally that can come from a broken lateral. I emailed Waterway asking them what low sand levels can cause. I have not heard from them yet. Any comments or suggestions will be greatly appreciated. I have a 30 foot X 52 inch AGP. My pool is green right now. I just purchased a Taylor K2006C testing kit but have not used it yet.