I had a submersible pump the first two years of my pond. Hated having to pull the pump out to clean the filter around it and also used more electrical energy. Pump claim to push 1950 gals but had barely a trickle on the waterfall. I have a Sequel pump which is very quite. My air pump makes more noise than the pump. The drawback to the external pump is that you may need more fittings, valves and a priming pot even if your pump is in a pump box below ground level. The priming pot catches alot of stuff that can damage the pump and also ensures pump isn't running dry. Don't know what size pump you'd actually need. When calculating head you calculate the distance the pump has to lift from the surface of the water plus the length of the pipe and any fittings for friction loss. You also have to figure out how wide your waterfall (if you have one) and how much flow you want on that. Someone on this forum probably knows how to calculate that stuff. Good luck!

I have a Tsurumi sub and a WLIM external. The external is actually quiter than the sub.
The sub is in my skimmer box so all I do is remove the filters and wash them off once a week.

In my first pond years ago, I had a sub at the bottom of the pond and I hated pulling it out of the water to clean the filter. Also, the pump on the bottom of the pond was constantly burning out and having to be replaced.

I use two mag drive sub pumps. One 3600gph in the skimmer and one 1400gph on a small ledge in the settling pond. Very nice, and easy for me. Also mag drive pumps are pretty energy efficient.
Lisa

No brainer, it has got to be an external pump if you have a choice.

I have a two submersibles - Laguna 7000 and 3000 (old model numbers). Very quiet...about the only way I know they're running is the water moving in one biofilter and the waterfalls.
Very efficient ... don't even see the impact on the electrical bill when I turn them on in the spring. I've had both pumps about 8 years now. Replaced the impellar on each once due to wear. I really enjoy not having to worry about them overheating or somehow losing prime and suction (a potential problem if you lose power). Both are in my skimmer box. Don't have to worry if they get wet either! LOL! I've got them both on union couplings so they are very easy to remove and change intake screens for cleaning.
---David

Get an external pump - lower hydro cost, easier to clean out each week.

The Sequel is very quiet.

I was woried about priming the pump - but that is easy if you install a back flow valve between the priming pot and the water. I now just fill the priming pot in spring using the garden hose, and it stays primed all summer, even when I open it for cleaning.

The only problem with an external pump is that it is external. If you want a natural looking pond you need to cover it, and the *$#& people that make fake rocks don't design them for pumps.

I have one of each as well as a very handy husband. this is an excellent combination!
The external pump is a ? is it a Sequel? 750, and it's ultra quiet. It's at the far side of the pond, there are a few plants in front of it, and I only hear it when I walk around to the far side of the pond. We have a double settling chamber in front of it, which catches everything and has an easy valve for cleaning. Much recommended! It's all ground level, so the pump uses hardly any energy. The submersible is a small one on the skimmer. That one zooms softly, but it's small, so no issue. Taking the filter sponge out of the skimmer is messy, but because it's at the surface it's not hard to do. I always switch the little pump off for cleaning (daily in spring and fall), but even so, after reassembling the sponge and the leaf basket, little bits of stuff often get into the pump or through the pump to the spitters, where it clogs the spitter outlet. We never have anything get stuck in the external pump.
DH is the one who brings the external pump in for the winter and puts it back outside in spring. Our winter cold would damage the external pump. We also bring the little internal pump in, since it's at the surface. If we had a big submersible at the bottom of the pond, we'd be able to leave it in the water (although not running) in the winter.

:) Mary

if you want a clear pond,put a settling chamber before your ext.pump.an internal pump works like a blender and mashes up the junk and the filters have tbl.cleaning it out.i built an over,under three stage settling chamber,filter before the pump.it works great.another good pump is the performance pro.it has more head pressure than most pumps

I have a WLim external pump which is very quiet and a Tsurumi pump in my skimmer box.
I prefer the external pump.

I use submersible pumps, I can leave them running all winter so the pond does not freeze over and I can leave the fish and have some less hardy plants, with the addition of a tank heater. It is a small pond though, I would likely go external if I expanded.

What kind of external pump do you recommend and who do you recommend to do the hard wiring? We have a broken submersible pump of 3600 gph. Any advice would be appreciated. Thanks, jackie

You first have to decide how much you want to pay. The external pumps plug into an electrical outlet. My Sequence pump has been on 24/7 for five years.