Does sump have to sit below tank?

I'm considering building a sump for my 30 gal tank. Pics are in this thread http://www.3reef.com/forums/show-of...al-built-into-entertainment-center-79969.html

My question is, does a sump have to sit below the DT or could it sit on the same level as the tank. Because it is built into an entertainment center my only option is to have it sit directly behind this tank in the entertainment center.

Or would I be better off going with a HOB refugium, which i think might create a problem because i don't have much clearance above my tank.

Any ideas would be appreciated!!

 

Sumps work best if you can gravity flow into them and pump back to the display. Or vice versa you could build a sump above the display, pump up to it and gravity back to the display I suppose. The trick is you don't want to pump both to and from as its impossible to get two pumps to always pump the same amount so one will outrun the other eventually and flood.

 

Should be below the waterline of the main tank. So it could be beside.
If you do something else make sure when the power goes out neither floods.

 

Yeah i definetely won't use two pumps. I have a sump on my 125 african cichlid tank so i understand how they work, but i want sure if i could have it sit on the same level. I would use an HOB overflow but not sure if that would work with the sump sitting behind the Display Tank.

 

I don't think it would work since you need an elevation difference to form a siphon. The levels would equalize and not move very fast if the tanks are at about the same height, even if you used a siphon since there would be little head pressure against it.

 

You wouldn't necessarily need a siphon, you could use a regular standpipe and use gravity to feed the "sump". I know people who use "compound" sumps where there is just a bulkhead in the side of 2 tanks with a straight pipe connecting them and a return pump in one and the drain coming from the display tank in the other and they work fine AFAIK. I don't see why this would be any different.

How much room do you have back there? If it's not very much a HOB might be your best bet. It might be really hard to work on the tank behind the other tank, have you taken that into consideration? The easier it is to access that stuff the more likely it is you'll keep on top of maintenance IMO.