I always recommend going to melevsreef.com and checking out his sump setups. As far as size is concerned ,the bigger the better. The bigger the sump the more stable the tank will be, because there is more water volume.
Are you considering adding a refugium? _________ 90 gallon tank with center overflows, 44 gallon custom sump/fuge, Tek T5 retrofit 4x54 bulbs, Reef Octopus nw200 protein skimmer, Iwaki WMD40RLXT return pump (changed to panworld 100pxx),Knop c ca reactor, PA light house controller.
Click: Real-Time Stats 
^^ Testing it out! Ill add more param.. later. | 
