I washed our PFS in a decent sized bucket in our utility sink. Just poured some out of the bag into the bucket, turned on the water, and used my hand to sift through it, getting all the way down to the bottom of the bucket and turning over the sand a few times. I would then dump most of the water and repeat the process 4-5 times. Took me about 10 minutes to do a whole 50 lb bag. The sand was fairly clean to begin with, so with washing it first, I had little cloudiness after putting it into our tank.