Overflow options

Finally getting around to making progress on my newby 120 reef- by that I mean about to start curing rock and obtaining remaining supplies. So still a long way from stocking tank.



My question revolves around the Mainland Cornerflo overflow system. It comes with a 1 1/2" inverted U drain (not quite a Durso- no vertical clean out) but does have a small air vent in that region but also 2 odd ~1/4' holes drilled at water line. The tube decreases to 1" as passes through the bulkhead at base of overflow. Also has a 1" straight additional standpipe designed to be for water return from sump.



I am paranoid about everything reef due to my initial short and fantastic failure 15 years ago (I haven't tried since...) Anyway, after lots of reading I have become fond of the idea of an emergency drain. Therefore, I am considering making the 1" standpipe into some variation of an emergency drain. Then, I will have to bring the return line up over the back of the tank, which I am fine with- don't really want to drill anything. My question is about what to do with the other 1 1/4' drain? For those of you with Marineland experience, is this provided drain configuration any good? Have heard it is loud and water level varies which adds to my paranoia. Should I switch to a conventional Durso? Should I use more of a Herbie like setup? I really like the BeanAnimal but don't have the 3rd drain hole needed.



Any thoughts on Mainland cornerflo, my idea or feedback about drain setup in general would be appreciated.



Thanks,



Bold