Internal vs. External return pump...

becact

New member
I am setting up my first real tank, a 90g. I am trying to decide between an external and internal pump. I need to make this decision because my sump dimensions will be affected by it!

How much heat does an internal pump really add? I am thinking along the lines of a Mag7. This tank will not have a chiller, so heat is important for me.

I'd appreciate any advice!
 
Mags are just awful in so many ways.
If you can get your sump drilled and have the room for an external pump.
1. Less heat exchange.
2. More options.

Sean
 
What would you suggest for an internal pump, then? Why do you not like the mag?

I'd rather not have the external pump just because that is more sump room I can fit. Plus drilling will add to the price (bit and bulkheads).
 
I beg to differ. I've ran MAG return pumps on both my 60G and 180G without any issues for years. If anything, it's given me more options since MAG pumps can be run internally or externally FYI (one of the reasons I chose a MAG). I'm currently running a MAG 12 for my return on the 180G and it's been working like a charm for over 3 years. I clean it (w/ vinegar) every 6-8 months and it's good as new. I've used one (MAG 3) externally on my old calcium reactor for years (5+) without issues and now use it internally (3+)as a feed pump for my Deltec skimmer. I'm not even sure how old the pump actually is because I got it used already attached to my old calcium reactor. It's at least 8+ for sure but easily be 10+ for all I know so longevity is not an issue. HTHs.

Minh
 
Eheims can also be used externally as well ;). I have one on my GEO reactor. Although, I don't know if Eheims can put out as much flow as MAGs (12, 18, 24s). I think Eheims are more efficient however.
 
Well, the Eheim 1262 is twice as much, which is what is keeping me away.

The mag7 will run 480gph at 4' of head, and my overflow can handle a max of 600gph. This sounds like a good match, right? I will be providing more flow, of course, with in tank pumps.
 
Mags add heat to your water so if heat is a concern i would look elsewhere. ( Ehiem is the way to go regardless of price)
 
<a href=showthread.php?s=&postid=14751354#post14751354 target=_blank>Originally posted</a> by becact
Well, the Eheim 1262 is twice as much, which is what is keeping me away.

The mag7 will run 480gph at 4' of head, and my overflow can handle a max of 600gph. This sounds like a good match, right? I will be providing more flow, of course, with in tank pumps.

You can use both holes in the tank as returns to the sump and just put the feeds over the top to where ever you want them. This way you will need less in tank pumps. You can usually double the flow to the tank and use only a slightly larger pump.

Whatever you choose to do remember to place a valve on the OUTPUT side of the pump to regulate flow to the tank.
 
<a href=showthread.php?s=&postid=14751354#post14751354 target=_blank>Originally posted</a> by becact
Well, the Eheim 1262 is twice as much, which is what is keeping me away.

The mag7 will run 480gph at 4' of head, and my overflow can handle a max of 600gph. This sounds like a good match, right? I will be providing more flow, of course, with in tank pumps.
I own Mag pumps and Ehiem, The Ehiem has better quality and is very quite. At 4ft the 1260 matches the Mag 7.
 
I dont know how Mag pumps have been stuck with a reputation of adding heat to the water, I have ran several and never had a problem. I would like to know if all these people who say this have ever even owned a Mag, are or they just acting like a parrot and repeating something they heard
 
Pumps are like any other piece of equipment that consumes energy. Some of the energy goes to moving water and some to heat produced by the operation of the pump/motor. They ALL will add some heat to the system. If you put the pump in the sump it will add alot more heat to your system. Set it up as external it will be air cooled and will add very little heat.

I ran all my pumps external (mags included) and found the tank temp rise was unnoticeable with them on. Im guessing the people who complain about excess heat addition have them running as internal (submerged).
 
<a href=showthread.php?s=&postid=14751354#post14751354 target=_blank>Originally posted</a> by becact


The mag7 will run 480gph at 4' of head,
It wont. I've had a mag7 and an Eheim 1260. Even though the Eheim is rated lower, it has a ton more flow in real world. The Mags lose a lot of flow due to head loss. The Mag7 was hideously loud which is why I replaced it with the Eheim. The huge increase in flow was a surprise that I wasn't expecting. The difference in noise level was amazing.

On the issue of heat. ALL submersible pumps are water cooled. They are cooled by the water moving through the internals of the pump. These pumps will add ~ the same amount of heat run internally or externally.

External pumps can be air cooled or water cooled. An air cooled pump (depending on how it is made) can add substantially less heat to the water than a water cooled pump. Air cooled pumps will be louder than water cooled pumps.

People seem to assume adding heat to the water is always a bad thing. It isn't. We run heaters in our systems to add heat. If your system runs hot and adding heat from a pump is a problem, an air cooled external is the way to go. If your heaters are on a lot (like mine) a water cooled pump will reclaim heat energy from the pump so your heaters dont have to run as much.
 
Well, my concern is that my overflow is only rated for 600gph, and I have read that you need to be below that to avoid too much noise, so I was shooting for 500gph or so. This is my first tank design, so please correct me if I'm wrong! Also, melev's reef suggests about 5 times turnover through your sump (and thus, through the return pump), so with my about 110 gallon total volume the 500gph is good, too.

Will the Mag7 and/or Eheim 1260 do this number at 4 feet of head?

Also, there are two holes on the bottom of the tank, hidden by the overflow. It was suggested earlier to use both as drains and PVC pipe the return up the back of the tank. Won't the two drains overpower the draining capacity of the slits in the plastic overflow, if I did this?
 
You got it right. 3 - 5x display size after head loss and less than the max capacity of the overflow. 270 - 450 GPH which is less than 600.

One hole (the large one) is all you need for the drain. The other is for return. You need a standpipe if you dont have one. Most people use a Durso.

An Eheim 1260 with the typical plumbing setup will do ~ 450 GPH. Mag7 will be less, but I dont have a number.
 
Thanks for the help! i found a local with a Mag7 for $40, so I may just go this route for now, unless I find it too noisy. I just spent a ton on lighting and misc stuff, so need to be careful, or else this tank will never be up, lol.
 
Unless you find an Iwaki. It is too a quality pump and they make for a good external design. Man, I sound like a shill. ;)
 
i run a quiet one...i cant notice a heat increase and the thing is pushing 6 feet and then some.

they are meant for both internal and external but i found out they see to be tricky running externally since they seem to leak a bit...ofcourse i always do something wrong so it might just be me.


eheims i hear are good but like you said they are expensive
mags...same good but they will kill your wallet.

quiet one pumps are like half the price of the ones listed above and you can get them in quite a few configurations
 
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