OK I have seen the post about this one and that one but in my experience this is what has happened to me. In my 75g. I had 12 Zebra and 2 Scarlet Crabs for a year and they did a great job and lived happily ever after, until I bought some cheap blue legs and in a year I was down to one large blue leg. I have since replaced him with one scarlet and four of the Cortez Reds. In my 155 I have 4 Scarlet and 6 Zebra and although they do rumble sometimes, I still have the same amount for a year. What is your experience?