Return Pump: In or Out of Sump?

[mrbee2828]

I'm planning my 40g breeder sump/refugium right now and was wondering about pump placement. I have about 36" to work with and I'm leaving 10" for a future, larger skimmer. Add in 2 baffle areas and I'm down to about 22"-24". I'm probably going to invest in an Eheim 1260 or 1262.

I'd need to leave about 5" or more for the return pump area. I see a lot of DIY sumps with the pumps submerged (including my first FW sump build). Given they can give off heat and would take up 5" on the sump, wouldn't I benefit from designing this without a submerged pump?

What are the cons of an out of water pump, especially with the Eheim models?

 

[NyteGTI]

Since you're in the garage and not in a bedroom or living room where sound would bother you, I don't see a problem using a pump out of the sump. I personally just like mine in there. You've got a good amount of room in your sump in comparison to your tank size. I wouldn't think that extra 5" will hurt you if you submerged it since you're running a 75 DT with a 40G sump/fuge.

 

[melosu58]

Moved to General Hardware and equipment discussion.

 

[Rutrag]

It also depends on how confident you are in drilling the sump and installing bulkheads and associated pumbing for water to feed the pump. External pumps generally require you to do this. In my opinion, the pumps that are marketed as either submersible or external last longer when submerged as the water helps to keep them cool (which is why they heat up the water). On the other hand, an external pump does give you more room in the sump (but requires more room some place else), doesn't heat the water as much, and may be safer since the electrical part of the pump (depending on design) is not exposed to water in the event of a housing crack.

 

[mrbee2828]

Do I have to do a bulk head? If I mounted the pump above the sump for example, couldn't I just plumb a screened/filtered intake to the return pump from the top? Does it doesn't have the pull for the water? I'm asking because I don't know not to be difficult.

Noise, I wonder how much more it would be... hhhmmm. It is in the garage so it's not super important but I don't want it to be annoying when we're watching TV at the bar or having drinks in there.

Space, true, I have a lot of space, but I could potentially have 5"x18" more space for the DSB and such

 

[Wy Renegade]

Somebody else correct me if I'm wrong, but most of the return pumps available in the aquarium hobby are just that, a return pump. They do not suction to pull water up and in, rather the impellar pushes the water up.

 

[Rutrag]

Somebody else correct me if I'm wrong, but most of the return pumps available in the aquarium hobby are just that, a return pump. They do not suction to pull water up and in, rather the impellar pushes the water up.

You are correct, sir. The water coming into them is pulled in a little from the displacement. This is why most HOB filters don't work at low water levels and just churn the same water over and over.

 

[mrbee2828]

Well that solves that! I guess sit will be in the sump