One other item you might want to keep an eye on. I have a similar configuration with my cooler mash tun. (False bottom connected to the ball valve with a rigid pipe.) I was having issues with gain getting past the FB. After three brews I realized that the weight of the ball vavle with a hose was causing the FB to lift up in the back of the MLT because the cooler wall was flexing and acting as a fulcrum. I wound up cutting the rigid pick up tube and inserting a small section of flexible tubing to all account for the flex. Works great now.