Hey, I currently have a 55g with only a 5 inch oscar. I've been recently thinking about getting a poly or more if i can. He and the poly/polys would be upgraded to a 100g rubbermaid pond during the summer. What would you recomend for a first time owner and would go best with the oscar. Also, this oscar is super mellow. He was in my discus tank for about 2 weeks while i found a replacement heater for his tank. Thanks.