I got a great deal on a 75 gal Clearview acrylic tank a year ago that has a center overflow . The stand that came with it barely has room inside for a 10 gal tank and that won't work for a 75 sump so I just put bulkheads in the holes and plugged them . I put 2 180 GPH pumps sitting on dollar store scrubbies for the bio and to dampen the vibration of the pumps . On top of that I have bags of Matrix with poly fil on top of those . Tubing goes to DIY spray bars at ends of tank . Works really well . I guess it is just an internal canister filter...lol Someday I will build a better stand and put a sump on it , but , it works fine as is for FW planted . That is why I plugged the bulkheads instead of gluing the holes shut . I can use them in the future . See pic...