if the tank is just cloudy from suspended sand silt then i'd leave the fish in there and do large water changes, being careful to add the new water back slowly and pour it over something, like a large piece of decor or a dinner plate. no sense in stressing the fish by moving them all over again twice, and who knows...... the extra water changes might induce them to breed
another thing that helps is to toss an additional hob filter on the tank, with paper towel wrapped around the intake and fill the filter full of polyester batting. this will help clear the water up faster.