I currently have a gravel base, and was thinking of adding a few patches of sand here and there for my coreys . How would I go about doing this? Can I just rinse it really good and lets say put some in a cup, put the cup in the tank get as close i can to the gravel and gently poor it? Without causing to much of a disterbance.. Maybe I can do a 25% water removal, add the sand. then take in just water for another 30% to get some of the cloudyness if there is any? Of coarse I wont be doing this for about another 2 weeks. Waiting for it to cycle. hopefully is just about done.