I just added sand to my tank too... and it was gnarly... however, I did a few things to calm it down... I got a bottle of Clarity from Seachem... Dosed my tank up with that. I also have a protein skimmer, and for a few days all it would pull was light brown "leftovers" of the aragonite sand i had just added. It was clear within 2 days though!
A piece of advice that i was told and worked for me is this... when adding sand to a tank with water already in it, get a big PVC pipe that is long enough to be on the bottom of the tank, and have plenty of the top out of the water... I got a funnel and cut the tip off of it... i rested the PVC on the bottom and filled the pipe up with the sand until the water was coming out of the top... then i slowly lifted the pipe and let the sand fall into place. There will be a lot of sediment still in the pipe when youre done, but it will be localized and wont be as bad as just dumping sand into the water. hope that helped!
