I have a river setup with a channel cat, bluegills, a yellow bullhead and a crayfish. I was wondering how i could make it more like the river system were they come from? ive made my water brackish as can be, black and brown gravel to mimic the river bed, lots of caves, rocks, ect, I have even gone into the cold rivers of Indiana to harvest plant life dose any one have any suggestions to make my inhabitants happyer?