So I'm upgrading from a23x13x15 wet/dry to a 36" sump/refugium. Currently running an Iwaki 40rlt I think,not totally sure ( it's 5-6 years old). I also run a Rio 3100, for my chiller, returned to the tank. My question is do I keep the iwawi or go with the Sicce Syncra 5 ? Already have the Sicce pump, if I go with it ....external or internal? As of now, I have no circulation pumps in the DT , but I will be adding Tunze soon. Not to sure about flow thru refugium (gph) am I trying to push to much water with these pumps? Heating the water? Any opinions or options? Thanks....