I just got a 4-5 inch rhom today. I just got him acclimated to my tank. He should love it considering the lfs's water was super high in nitrates. My water is better!!! I was wondering how i should measure for tl? Also he is in a 20 gallon tall. How long can I keep him in there? His eyes have not yet changed to red either...but it will be sweet when they do!