Okay so I am putting together a list of things I want to do to my tank (40g breeder) and after replacing my bulbs a skimmer is my top priority. For a while I was going to go with a sump but after going to my LFS the owner suggested a HOB skimmer as he said overflows can be a pain in the ***. Drilling is out of the question as I have no where to store all my stuff. Another issue is as far as sumps go I would be pretty limited for space as the inside is only 36x18 and I will have to get back to you on the height. As far as HOB skimmers go I was looking at the octopus 100-ss. I would like to be able to have a refug but if I go with a HOB that seems to be out of the question. I going back and forth between HOB or go for the sump. Can anyone with experience with overflows and HOB skimmers give me their two cents?