Also, take a look at your MLT before adding grains.
Set it up near a sink or outside and leave the valve open. Add water to it until it starts to come out the spout. Stop adding water and let the water finish flowing.
Close the spout, measure the amount left in it. This is the dead space in the MLT that doesn't drain. Because of the way I have mine setup, I lose about a quart. Yours may be different, but you should factor this into your volume calculations.
If you can't do it with apathy, why bother?