Originally Posted by Accidic
Not really following you on the hose elevation on the outside of the cooler. I'm about to switch mani's to CPVC but previously the mani I linked above pulled out all but a cup or two at the absolute most with no issue and I had the hose going straight down from the outside connection into a pot. Could you elaborate a bit on what you mean by getting enough elevation on the outside? Thanks.
Yes. The distance between the end of the spigot/fitting, to the bottom of the receiving vessel (well, technically, to the top of the receiving vessel's volume).
If your manifold is flush with the bottom, and that the liquid has to go up 3" to get to the valve, you will need at the very least 3" of head (downwards hose) to create enough head to keep pulling to the bottom of mash tun. In reality, it's higher than that as there is friction. If you were testing with no hose (only the ball valve & fitting), that's the source of your larger than normal amount of liquid left behind.
Also, the hose should be small enough to prevent ANY air from being in it. 3/8" to 1/2" should do it.
Refer to this discussion here: http://www.homebrewtalk.com/f51/mash-tun-manifold-suggestions-327949/