External vs internal overflow

Reef.Blue · Dec 29, 2023

I’ve been reading through a number of posts through reef2reef pertaining to the debate of internal vs external overflows. I feel like it’s a 50/50 but I’m leaning towards external before I pull the trigger tomorrow. I’m looking at ordering the Innovative Marine nuvo 100 reef ready system. Any insight is helpful.

TangerineSpeedo · Dec 29, 2023

I have both, well actually all three types. INT, EXT, AIO. If it was fish only, any would be fine. Having live rock or corals, EXT is the best. Flow is your friend and with an INT it is just too many corners to get around, disrupting flow and cause detritus build up. With the IM there isn’t even a overflow box to get in the way. If for some reason you needed to get your tank against the wall, then an INT would be your choice. But IMO you do not want a tank too close to a wall just for maintenance and cleaning etc.
EXT would be my vote...

Reef.Blue · Dec 29, 2023

TangerineSpeedo said:
I have both, well actually all three types. INT, EXT, AIO. If it was fish only, any would be fine. Having live rock or corals, EXT is the best. Flow is your friend and with an INT it is just too many corners to get around, disrupting flow and cause detritus build up. With the IM there isn’t even a overflow box to get in the way. If for some reason you needed to get your tank against the wall, then an INT would be your choice. But IMO you do not want a tank too close to a wall just for maintenance and cleaning etc.
EXT would be my vote...

How far from the wall would you keep the tank?

FMF0331 · Dec 29, 2023

With EXT , I would keep mine at 8" - want to make sure I have plenty of room just incase ( with this hobby .. Murphy laws is our best friend )

JM302 · Dec 29, 2023

Once you go external, it's hard to go back. The only other negative to the EXT is the plumbing isn't quite as straight forward, but still easy enough. Only because I was curious, I checked to see how far my EXT170 is from the wall.. it's just at 6". Although not easy, I can fix anything with the plumbing if necessary. The good thing with IM is the bulkheads are removable while pvc is glued in.

ThaBeast · Dec 29, 2023

Having had both of various styles, I only purchase external overflow tanks now

TangerineSpeedo · Dec 29, 2023

Reef.Blue said:
How far from the wall would you keep the tank?

My 40g is about 5" , but I wish it was a bit farther. The Neptune feeder needs some space to overhang with the USB cord, I am not sure how much you need with the @AVAST Marine feeder, but you need some room with that also. Plus there is always the time the wrasse jumps and lands behind the tank and gets covered in dog and cat hair. So its good to have room to vacuum behind once in a while.