Actually, I wouldn't do that - mix the sand up. Sandbeds have distinct strata that setup and do specific things. Mixing it screws all that up. Just add some more fine sand over time until you fill in the gaps. You don't have to do it now, just eventually. As soon as you get the stirring critters in there they'll do the mixing, but they'll be a heckuva lot more gentle with the process than you will be. Like I said no hurry, in fact you could just buy a small bag of the dry sugar sized stuff and add it in a cup at a time as it is convenient. That'll keep the sand storm effect to a minimum, as well.
DJ
DJ
