I currently have a 55 gallon tank for 3 small goldfish and a 3 1/2 inch painted turtle... it seems like a waste to have all that space for just that little bit of animal so i wanted to combine on one side of the tank the fish and the turtle, then get a tank seperator and put my two tiger salamanders on the other side. I am worried that the salamanders waste will hurt eithier the fish or the turtle. I have seperate filters for both sides of the tank. What do you guys think? Thanks. Lisa