So is it better to somehow remove gravel to put in like sand or even new gravel or just put it over top the older gravel? or does that seem tacky or just look bad? but heres the question in more detail, how do you get out the gravel for something new? i have some fish in the tank so would it damage the fish or would they be fine if they got hit by the sand/gravel? should i take out the decorations when putting new in? im thinking bout going to a natural gravel or maybe some good fine sand..