What size pvc should I use for a mag 18?

What size pvc should I use for a mag 18? From what I have heard online if you use anything larger than 3/4'' you get more flow. So i was planning to use 1 1/2''. There is this aquarium place in mineola called Rivers and ponds they also install ponds and aquariums so they know their stuff. Well they told me if I use anything larger than the 3/4'' I would lose all my pressure...Now what to believe?

 

:-/ I have the same pump and I use 3/4 that's alot of water..I think they maybe right.

 

I have a mag 18 and I'm using 3/4". If you plan on having multiple 90 degree angles on your pipe you might upgrade to 1" or 1" 1/2.

 

I also have a mag 18 and am using 3/4". The pond store is right you will lose pressure. That isn't a bad thing though. You don't want to blast your corals. You want high volume/gph and low pressure. A larger pipe won't hurt any it just may be harder to plumb.

 

mag pumps says to use 1 1/2 " pvc. I have the same pump and used 1" for the return then teed with 3/4" three times to the tank.

 

you can look at the pic's of my sump setup on the this web site under (sumps)

 

What do you mean? I thought with high pressure you get more GPH does higher pressure=higher GPH?

 

btw I am having dual returns