Yeah, i know i shouldn't rush the corals. But, i have added corals to tanks at times shortly after cycling and had little problems. But, it also depends on what you are adding. Lps and sps corals are not going to fare well for sure in a recently cycled tank. In regards to the sand, I am already using 2 inches of aragonite sand in the main tank. I will be adding some more from already setup tank(over two years). I just need to fill my sump up some more with some sand. I am just wanting to make sure that if i use cheap sand to do so that it doesn't cause me any problems in regards to water quality, algae blooms, or any other harmful things to corals. but i also think that if it isn't necessary to spend 80 dollars on sand when i could spend 15 to do the same thing, i would rather go that route. I am just wanting to see what everyone else thinks and their experiences.