Advice for new overflow?

[NancyFish]

Is it better to size up, we have a 65g tank? Should the return hole be the same size?

Is Eshopps really the best overflow or just most common? Any experience with prodigy vs eclipse?

Does placement make a large difference, like center back, side back, side panel etc? If so does return pump placement make a huge difference or just our preference?

 

[KrisReef]

Drain hole is generally larger than the return. It has to drain with the force of gravity moving the water where the return has the power of a pump moving water, so a smaller return is matched to a larger drain.

Everyone has the best return, or siphon, or style. Look at what they are rated to handle as far as water flow and get the correct size for your tank, or larger if it comes with an extra (safety) drain. Two drains can save you a lot of pain in an emergency drain hole blockage scenario. Singles scare me, but they can work fine on other peoples tank setups.

Where the overflow goes impacts the flow in the tank. Lots of tanks have the return on one end and the overflow on the other. Some have the return and the overflow in the same corner, or middle, or side panel of the aquarium. They are not pretty to look at, imo, so I put them where they fit and hopefully in a corner or on the back of the tank so it doesn't obstruct viewing.