Internal or external return pump question

I'm in the process of setting up a 120 gallon tank with about a 50 gallon sump. The tank came with an internal return pump. I'm at the point that I have to decide whether to go with internal or external return. I know I'd have to drill a hole in the sump. What I'm wondering is, what are the advantages of using an external? How great are the savings in power usage? This is my primary concern after last months electric bill. I also know that it would discharge some of the heat outside of the water. Thanks in advance.

 

I don't think there are any advantages to most external pumps unless you have very high head requirements like having your sump in a basement.

Some say it will run cooler but that is not always the case since pumps that are designed to be either internal or external have water jackets or internal passages in the pump where it circulates aquarium water for cooling. Some strictly external pumps use a fan for cooling but they still have a stainless steel shaft and that shaft transmits heat to the pump end acting like a heat exchanger. Plus most external pumps I have been around are louder than a submerged pump so noise becomes a concern if it is in a living room or bedroom where quiet is needed.

Another advantage of internal pumps is they allow more room in the stand for other equipment like calcium reactors, kalk stirrers, CO2 bottles, GFO,Carbon and BioPellet reactors, external skimmers etc. They don't require drilling or an additional isolaton valve to work on them either. Having had both I prefer the submerged pump.

 

Thanks for the reply ADR. That's a relief being already set up for internal pump.

 

If you don't already have a pump, take a look at the variable speed DC pumps. I bought two for my main tank, but they were just short of the flow rate needed at the high head height I've got. I had to resort to going back to my old power sucking 4.4 amp pump.

However, all was not lost! I am using the two pumps to power my 14' waterfall... great flow for 87 watts per pump.

 

I have an internal pump that came with the package that I haven't set up yet. As I have not got this system going, I wanted to look at the possibilities. I'm trying to figure out, if in the long run, is it better drilling for an external. So far, it sounds like it might be more hassle than its worth.

 

I prefer internal pumps. One less place for a leak, but I'm sure others might feel differently. I'm a big fan of keeping everything contained as much as possible. Good luck with the set-up!

 

Go internal. I don't really see the need for external unless you need a big head

 

To my relief, it's unanimous. Thanks everyone for the input.

 

Did you say what the head height was going to be?
I'm currently using a DC12000, with a 10ft head height.
I'm using 1.5" all the way up, with as few bends as possible.
I too like internals.
But as said, atm, the products that will push even more flow/head are external.