I can't decide between crush coral sand or crush coral. From the research I've done most of the people use the sand or aggrigate sand. I'm afraid that the sand might end up in my FX5 filter as the turtle flips it around. The crush coral that I've purchased today (and also have some left over) is the smallest grain before it's classified as sand. The sand is the #0 and this is the #1. Do you think it'll be too coarse for the little fella of 5"? Thanks in advance.