I'm looking for tank mates for my school of corys. The youngest of the corys are around 7 yrs,the oldest,a female, is 20+. After rehoming a common pleco and 2 large goldfish,(thanks to OHIO FISH RESCUE) i was able to move my 22 corys to their 55gal. forever home. The corys are top priority. Would like 1 or 2 medium size fish to occupy the upper water column without causing mayhem.i have researched this extensivly,and still havn't found any satisfactory options. Any suggestions would be greatly appreciated.