I was thinking of getting discus fish for my 55 (these ...http://www.liveaquaria.com/product/prod_Display.cfm?pCatId=850 ) . My first question is, how much can i put in a 55. Second is would they be best kept in a 55 with a wet/dry and a ac110 hob or a 55 with a eheim 2026 and a ac110 hob?