New 150 Return Plumbing?

If you were to do it again... I am going to take down my 90 mixed reef and set up my new 150 from Glass Cages. Purchased used on Craig's List. It is 48 x 24 x 31. I am going to have 90 lbs of Live rock and 150 Lbs of what was live rock. 30 gal refugium. Bubble-Magus BM160 External Skimmer. My return pump is a MAG 18.
My question is How would you run the return lines into the tank? My thought is to run them down the outside of the internal over flow to wash the sediment from behind the rock. I would use power heads for the waterfowl in front of the rocks. Is this a good idea?

 

I don't quite get what you mean about the return line's placement, but powerheads should be used for flow in the tank itself anyway.

I would make sure outlet of the return line is very close to the surface, at or above the level of the overflow's lowest point. Otherwise, you'll get a siphon.

 

I was going to run the return from the top to the bottom with 2 or 3 outlets to wash the water from behind the rocks. I would have a small vent hole near the top for a siphon vent.

 

I wouldn't do that. Just use a powerhead or two in the back to give you flow back there. Use the return for surface agitation. The hole is risky; any manner of crud can clog it, and there's only a minute or two tops before it can flood your living room.

 

Thanks for the feedback. I think that I will take your advice and save myself some trouble.