Internal vs external

I had a Mag 9 return and two Mag 7s for a skimmer and chiller. I got a Ehiem 1262 which saved about 20 watts, a new skimmer that saved about 50 watts and ditched the chiller all together saving 70 watts. That was a 140 watt heater running 24/7 I took out.

But I then mover from a acrylic sump to a glass sump and moved it into a closet that is on the outside foundation wall. That made me run more heaters in the Winter. I insulated the closet a bit which helped and I could have insulated the sump.

On the hottest Summer days I needed a fan when the halides were on. Small fan and very effective.

So there is a ton that you can do for heat. If an external will be enough to keep you from using a chiller, then by all means do it. It just depends on what your heat inputs are, what you can change, and how much of a change you need. A fan will do in most cases once you get everything else taken care of.

 

I went from a Mag 24 to a Dart mainly for the power savings. IME, for what is available, external pumps cost a little more, but use less power to run, and are generally quieter.

Some of the noise generated by internal pumps can be dampened by using spa-flex to the pump to stop vibration.

In my case, I was looking at this:

Mag-Drive 24
Flow Rate: 2,400 GPH
Power Consumption: 265 Watts

Reeflo Dart
Maximum Flow Rate: 3,600gph
Average Wattage: 145W

The Mag 24 was a good pump with great head pressure, but it created a very audible hum. The Dart is nearly silent, and uses less power with more flow.

You have to figure out what your head pressure will be, and look at the pump curves to determine what is right for you.

 

the pump external is better because the heat is very small and you save space in your sump