Return pump

[steveoutlaw]

Ok, what are the pros and cons of the internal vs external return pumps. I know that there are some nice external pumps out there, but I have this fear of having a gasket or seal break and ending up with tank and sump water all over the floor!

[Coral Hind]

Internal pumps can add a little heat to the tank but if a little heat added to the tank is not an issue for you then I would go internal. No fears of leaking seals and they are quieter then external pumps. It also depends on what space you have in the sump.

[Rosco's Reefs]

Never thought about that as an issue...

 

My problem with external pumps is that they have to be plumbed so they can be "primed" before they will pump. I learned this meant they have to be sitting in the water flow (water inside the pump) before they will pull.

 

I was trying to build a water change system that required the pump to pull water up and out of my sump...had to change my design.

 

Other than that, I think they are more noisy than internal pumps. Thx

[Max Ivers]

A key about internal pumps is that the electrical components are underwater....common return pumps like Mag Drives can leak current which can give you a good jolt if you aren't careful.

 

FWIW I love my Reeflo Dart/Snapper Hybrid External...it's incredibly quiet, never has leaked, and moves a TON of water. Also for an external pump it is pretty small (not red dragon sized, but not red dragon priced...)

 

A final thought...if you put a check valve on an external pump and prime it once, it should stay primed even if it's above the water line. Reeflo provides a diagram of how to plumb their pumps like this.

[Coral Hind]

Never thought about that as an issue...

 

I know of one member here that recently had a seal fail which let his top off keep running to make up for the water being lost onto the floor. This top off running through a kalk reactor crashed his tank.

[Max Ivers]

If you have the cash, go with a Red Dragon pump. They're a pretty penny but they can be run internal or external, and don't have seals to leak when run externally. They're also SILENT (~28dB that I saw in a youtube vid)