I just used it straight out of the bag. Didn't quite pour it, but that was due to space/logistical restraints
I scooped some out with a plastic deli cup/tub, and then dumped that in the tank. if there were clumps I would break them up. Added about ~1.5 - ~2", and then wet it down to a slurry, and smushed it around some to make sure it's distributed and such.
I had minimal clouding, but I think that was having a fiarly fine crained cap, and a very slow, non-disruptive filling.