Help with new aquarium

[Saltie]

Hi, I have been out of the hobby for some time, and find there have been a lot of changes...... I just picked up this 125 gallon second hand yesterday and I am stumped..... can some one help me figure out how to plum it???

Here are some photos, the tank has 5 holes in the bottom, one for the build in overflow (that is nice) and 4 others that I am not sure what to do with. There is a return on the back.... I have the overflow and the return figured out but what about these 4 other holes.

The guy alos through in a sump and a skimer to the likes that i have never seen before. I would like to use the sump, and add a refuge, can anyone help me figure this out?

I have photos posted in the equipment forum, please help!!!

[ret25yo]

ahh .. i bet the "return" is actually a closed loop drain (to a pump then out of the pump to your remaining 4 holes on the bottom.)... and the actual returns were over the top.

[Saltie]

Thanks for the help. Unfortunetly for me, I am a simpleton, and dont know how to make it all work. How do plumb it?

[Nikki]

Saltie, there are no pictures in your post?