I have sms in my tank and I only washed it a few times.. yes the tank was cloudy when it first got going but after an hr or so it cleared up.
sms will move easily when your hand is swished over it for quite awhile. it is light and airy for awhile until it gets settled in.
what are you using for filtration?
The problem was a simple light wave of the hand over the SMS, or a little fiddling of trying to place something in the SMS, and smoke clouds appeared. And I'm not talking about just the SMS moving, I'm talking about the dust clouds. Just thinking about the 10 or so cories I wanted in this tank, and the clouds I'd have while thier snooting around, made me re-think my substrate.