Internal or External Return Pumps: Which do you trust the most?

[MSarro27]

Internal Simplicity 1000DC on WB 40.1

 

[Sailingeric]

Never had the need for an external (would love to HAVE to have one with big tank and sump in basement) but an external would scare me. With my luck that would be the part that leaked and made a big enough mess that my wife would shut it down. Not so much the pump leaking just the DA that did the plumbing to it. For now I’ll stick with the Varios 2 that is an absolute machine. The last 3 years I have managed to have to replace everything due to wear and tare except the varios. I even have a brand new back up in the box that I have had for a year just waiting for the old one to die. Very impressed with these returns. I run it at 3/4, 24/7 unless I am doing a water change.

Like you in would afraid of leak and my Varios 4 has been running like a champ. I pull it out every 6 months or so for a good cleaning but it is a silent as the day I got it.

 

[BCSreef]

When setting up a new system one of the biggest decisions is what pump to run as your return pump which is the heartbeat of the system. Normally we talk about the make and model of the pump but today let's talk about why type of pump, external or internal!

Panworld 200PS for basement sump return. My backup is the same model pump on my skimmer.

 

[ThRoewer]

Internal so that I can use the heat from it to heat the tank in the winter...
I use Jebao DC pumps. I rather go with cheap and have an extra on the shelf than with expensive ones which may still fail but of which I couldn't afford a spare sitting around.

 

[nesty427]

I like internal if the ever leak a little it’s not on my floor

 

[scardall]

External pumps are the best to use because they outlast Internal pumps and Do not heat the water as well.

Internal pumps do not require a bulkhead, take up less space overall, heat up the water and DO NOT last as long.

 

[Seascapes]

When setting up a new system one of the biggest decisions is what pump to run as your return pump which is the heartbeat of the system. Normally we talk about the make and model of the pump but today let's talk about why type of pump, external or internal!

1. Is your return pump an external or internal pump?

2. Why did you choose external or internal?


image via @geo

I have an internal. When I got the tank there was this no-name in the tank and it kept ceasing. I just put in a SICCE 7.0 and I'm loving the control.

 

[Shooter6]

I had an external Reeflo Hammerhead pump on my 220 when my sump was in the basement. I needed something that would flow 20-30 feet of angled head pressure upwards from the basement. Now, I'm using the same sump on my 340 but they're ten feet a part. It's probably overkill. I had to put a manifold on and redirect the flow to other devices. So, I now run a cannister filter (25 micron) and ATS scrubber off my return pump with virtually no flow loss (in fact might be too much flow to the display). So, I just used the same pump instead of starting over. I bought a second of the same pump for my water change / mixing station. It's way over kill but no powerheads needed to mix salt water now.

Plus I have a backup if the main one dies with the same threading, size pipes, etc. The only issue with the Reeflo pumps is that where the pipe threads into the pump even with thread sealant and thread tape, etc, the outlet leaks. I put a half a bottle of liquid thread sealer on and around my return pump and so far, in two years of running, no additional leaks than from the first few days it ran.

That said, the pump has run for two years without being cleaned or dismantled with no loss of flow. How many can say that about an internal return pump that constantly builds up calcium and degrades due to being submersed in our adverse salt water conditions? I expect at least another 10 years out of the external pump. I turn it off once a month for maintenance on the tank or to glue corals down, it's never failed me.

I have also used the reefflo, actuLly have a hammer head sitting in my pile of equipment. They are good but do spring leaks at the seals.
As far as calcium buildup, i dont think they suffer from it in the same manner as internal pumps, but definitely do suffer from it on the impeller/housing area. Id still pull it off and clean out the wet side. The bearing will get calcium buildup also.

 

[ClownWrangler]

On my 29 gal I Have a Coralife HOB with a built in skimmer and the pump sits inside the tank. It is absolute garbage. It puts alot of noise in the tank and rarely skims correctly. Too much noise can literally make a fish suicidal and it will jump to its death. (I had it happen). On my 20 gal tank I have an Aquaclear 70 HOB that is whisper quiet and has an external pump. The filter compartment holds enough chaeto to do it’s job well for the tank size and it generates very little heat. Also, the laminar flow from it is far more efficient than the turbulent flow out of power heads in terms of circulating water in the tank and atmosphere/water interface turnover for gas exchange. I say for tanks that run heaters, a submersible in the sump is the way to go if you have a sump. For tanks that run chillers, go external for sure. Over all system efficiency is key here.

 

[MartinWaite]

I used use an external pump 25 years ago it was a gounfus central heating pump well the motor was the pump head was a plastic screw on and I needed it as my sump was over 20feet away from the display tank which gravity fed the sump. Nowadays I run an internal pump although it can be used for either way but I have the room in the sump for the pump and room is a premium in the cabinet. To be honest I also prefer the internal pump as I can remove it without any small spillage that is inevitable with the external due to that bit of water that's in the taps etc. Plus it's a weak point in the system for potential leaks.

 

[Delatedlotus]

There is ONLY one external pump I would ever both buy and use. I bought a **Japanese Iwaki 100r** 23 years ago it pumped right at 2160 gallons an hour, 36 plus gallons per min at a head height of 39ft at 25psi. I run 265 gallons plus total on my system. 2 tanks a 90 and a 110 and a 100 gallon sump of sorts, it is a 100 gallon plastic horse trough with my sump in it lol. Heavy duty pumps these are and with a huge head height. It went bad on me right at 4 months ago now. I bought another one from BRS ( I shopped very extensively both new and USED 1st ) for $478 dollars free freight. I would use NO OTHER PUMP PERIOD ..! It lasted right at 23 years! 365 days a year, 24-7, for 23 years. That breaks down like this.. 24 hours a day, 7 days a week = 168 hours a week, 168 hours x 365 days a year = 61,320 hours in a year, 61,320 hours x 23 years = 1,410,360 TOTAL HOURS THIS PUMP HAS RUN NON - STOP... Now someone out there tell me is there a better pump out there..? I have never changed any part on this pump ever, not an even the impeller. No other pump will last this long ever! They have never changed anything on these pumps at all. I did talk to the factory direct no changes ever on them. And I did get the dark gray replacement pump just like "I" had before, again bought the new one from BRS aquarium ** Japanese only. No other pump will ever last that long ever... NONE...

 

[caseym1211]

I assume you meant internal/external as configuration not submersible/dry .

Wouldn’t that be the same thing.

 

[Trand1983]

I did internal for my return pumps, I don’t have the room for external on my new build.

 

[Blknovass]

I have an AIO so internal pump. But in my old tank I had a sump with an internal also if it started to leak would not destroy anything

 

[Naso180]

When setting up a new system one of the biggest decisions is what pump to run as your return pump which is the heartbeat of the system. Normally we talk about the make and model of the pump but today let's talk about why type of pump, external or internal!

1. Is your return pump an external or internal pump?

2. Why did you choose external or internal?


image via @geo
External all the way if you have the space. They last longer, don't transfer as much heat to the water, cost less, are far less likely to leach metals into the water, and are less likely to electrocute you since the cord isn't in the water. Most of my return pumps are internal/submersible because of space constraints, but I wish they were all external/dry!

 

[Dos]

Internal only for me. The idea of an external pump or skimmer is just terifying. If it were to start leaking I'd much rather it leek into the sump than on my floor. Plus I don't like the idea of drilling through my sump in order to install a pump. Instead, I upsized my sump to accommodate plenty of room for pumps. Only pump I've had fail on me was a Mag 9. Now I'm all DC pumps and loving how quiet they are.

I personally also prefer the look of everything being in the sump. Keeps it all together.

Related to the question, I have no idea how anyone puts in an external skimmer. With as many times as my skimmer cup overflows, I'd be flooding my floors monthly. At least a return is totally closed and would only make a mess if it leaked.

which model do you use?

 

[RedReefer]

In sump for me. I’ve never had a tank over 125 gal. That’s probably the reason, That I’ve never looked into an external pump. I’ve always bought quality pumps so far I’ve been lucky and never had a return pump go out with a routine maintenance. Routine maintenance for me is probably a once a year cleaning...

 

[Sleepydoc]

It really depends on the pump for me. There are dedicated external pumps like the Iwaki and Blueline pumps that are tried and true, as @ca1ore stated. Then there are the internal/external pumps like the Varios, Ecotech M1/L1, etc. From what I've seen, almost all of these are designed to be water-cooled and many don't have very good cooling for external use, making them more likely to fail.

 

[tigre44]

I have a 55 gal with 20 gal sump in the basement. I have a supreme 9.5 and pump about 10’ vertical seems to work fine I am concerned about how much flow I actually get with 10’ head. I prefer an internal pump less chance of water on the floor.

 

[Grallster]

External. I have an Iwaki that I’ve had for 20 years that I alternate with a 10+ year old Panworld. Ball valve unions on both sides with the same plumbing. I pull one for cleaning and swap it out with the other. A couple of months later, I do it again. Takes about a minute and a half.