racking from kettle, or into bottling bucket?
from kettle, simply before you cool it, stir it in a circular motion and all of the trub will be in the middle and you won't get any trub.
from fermenter to bottling bucket you will always lose some beer, but a gallon is an awful lot.
i would put it more than 1/2 inch under water, make sure there are no hole and the hose is attached to the racking cane securly.
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