I rinse it in a bucket in the laundry sink (when I had this in the former house), or now in the downstairs bath tub. If you are careful you will not have sand going down the drain. In a 3 gallon bucket I put 4 or at most 5 cups of sand, then run the tap (warm and cold or your hand will get very cold) into the bucket and swirl the sand around with your hand, then gently tip the bucket and the sand will sink back down while the dirt/dust is dumped out. I repeat this 4 or 5 times; the water is certainly not clear by then, but that doesn't matter. There is only so much water I want to waste.
Dump the sand into the tank, then when you have what you want, do the hardscaping. You can add a few inches of water to enable you to plant--you won't be able to see through the water but that is OK. When finished drain out all the water right down to the sand. Then fill the tank using a large bowl into which the water stream is directed, this will avoid stirring up much of the sand.