I am think of setting up 20 long gallon tank and want something different then rbp. I love my reds but want somthing a little more aggressive. A p that is not so skittish. I read about how these people own Rhoms and they attack your finger through the glass. I was thinking about a rhom, gold spilo or......., someone help me out. If i did get a fish i would get it at 1-2" and how long could it live in 20gallon long. tank size is 30x12x12. What kind of filter if i decide to set this tank up would you recommend.