My tank is an elos120, it's a marine tank, therefore it has a sump. As per marines the sump gives you somewhere to hide all the ugly equipment that we don't want on view in the tank.
ln the first chamber of my sump l have 2 x eheim large internal mechanical filters, second chamber has my return pump and a couple of bio filters, l'm very happy with the set up. l did use an up atomizer for C02 injection, l found the atomizer really affected the flow of my return pump. l'm waiting on the post for a new atomizer to have ty-wrapped to my return pump, l'm hoping all the C02 will get sucked into the return pump and then into the display.
Mike