Vacuuming Sandbed

[csnow]

I vacuum about 1/4 of my bed with each water change. I installed a PVC valve in my gravel vacuum hose and I can use the valve to keep the flow at the right amount to get the black junk but no sand.

I have always done this so no experience with whether it actually makes a difference. I get a lot of gross looking stuff out though so it must do something.