I recently purchased the false bottom screen for a 5 gallon cooler. I connected it to my valve in the bottom with a piece of tubing. I recently did a brew and after my mash time was up I went to drain the wort off and only a few ounces came out. What went wrong here? Do I need to place a grain bag in the bottom to keep any grain from getting through. I'm wondering if my valve got clogged with grain. I didn't waste time figuring it out I just dumped it into a grain bag and sparged over the grain bag. Any ideas here? Has anyone had this problem before?