Originally Posted by JVD_X
You are running off to fast - reduce your run off rate.
+1 to this. I use 1/2" silicone tubing and I have done away with my false bottom (only use a little sink strainer over my exit port hole in the center bottom of my MLT). I barely open my valve until the hole tubing is filled with wort, then I start opening more. I am going back to using a grant instead of directly hooked up to a pump due to sticking mashes. Gravity into a bucket and pumping from there is much more gentle on the mash than even restricting a pumps suction. I had never had a stuck mash until I thought I didn't need my grant anymore. I Has Learned!
Go slow no matter your setup and you will be thankful for it.