This is a discussion on do I need to drill? within the Beginner Saltwater Aquariums forums, part of the Saltwater Fish and Coral Reef Tanks category; -->
How hard is it to start an SW tank with out drilling? I dont think I will be using a sump since it is ...
yes, however adding a sump adds more water volume. the more water volume the more stable your water parameters will be. a sump also allows an in-sump skimmer to be used, a place to put heaters, carbon/phosban reactors and refugiums with macro algaes. you could use a hang on overflow which allows you to have a sump without drilling but IMO i will never use one again after using a glass holes overflow box, and drilling isnt hard as long as the glass isnt tempered.
I have had a positve experience with an overflowless SW tank. The hang on the back type protien skimmer worked good, no complaints about the media filter/bio cartridge filter setup either. But think of it this way. All the pluses of the added water volume of the sump style makes for less maintenance and if you enclose the sump inside the tank stand with decent doors, It could be much quieter than having the filtration mounted right to the top of the tank, not to mention much nicer looking too.