quick ? on over flow systems

Would it be benificial for me to have one on my 16 nano reef system and if so ive never built one any good web sites to explain building one. Thanks

Usually if your tank is not drilled you need an overflow. i.e. some method of getting the water out of your display tank (DT) and through your filter, heater, skimmer, pump etc and back into your DT. Overflows are such a system as that. Oh and it helps to maintain tank level for evaporation and a place to add water for dosing. BUT all that said, I am in the process of installing a 5 gal nano for a quarantine tank. It will have no sump, overflow etc. There are not many things you MUST have. Delbeek has a minimalist tank in the sunlight, (supposed to be a big mistake) no sand, small amount of LR, toss in a bag of activated charcoal. But you will have lots of hands IN work and testing to maintain.

The overflow itself is easy. You can use glass or acrilic. Use silicon for glass or weld-on for acrilic. Make a box for a corner, coast to coast( goes allthe way across the tank), or center the box in the middle. This is how mine is set up, may be a little over kill for you as it will handle 2000 gph, you can use 3/4 in pipe and still handles 1000 gph. http://www.beananimal.com/projects/silent-and-fail-safe-aquarium-overflow-system.aspx
The one I use is called the beananimal, then you got the herbie method, the durso or stockman stand pipes. For your tank a durso or stockman set up would be plenty with 3/4 in pipe will handle 300 gph I believe. Requires 1 hole and a overflow box. The overflow can have teeth but doesn't have to. You can do themin tank with a fasle back also which wouldn't reqire drilling the tank. If you drilled the tank and add a sump it increases your total gallons which makes the system more stable, allows you to hide heaters, pumps,ect. Place for fuge to grow macro algae, put skimmer, grow frags. I think you get the idea.

It's up to you basically, I never run sumps on my nanos, I'm ok with seeing a heater and don't run hang on back filters or skimmers though, just rely on the rock for filtration and do weekly water changes. Drilling is always the safer way if you want a sump though, I've heard too many stories of hob overflows failing.

Melev's reef has good info on overflows and a bunch of other stuff.

http://www.melevsreef.com/