Mag 18 PVC size Plumbing? Help?

[Reef Guy]

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?

 

[House of Laughter]

believe the manufaturer - it has a 3/4 outlet for a reason. Use it and deal. I personally don't think there is any benefit to MAG drives over 9.5 as you can get better pumps/

My .02

House

 

[cali_reef]

You won't gain any more flow than what the pump is rated for and you won't lose any pressure if you use bigger pipes, unless you are using pipes that are extremely large for the pump or you have a leak somewhere. A slightly larger diameter pipes will provide a less restrictive flow path, especially at each point the flow path is making a turn. I would use a 1 1/4 inch pipe for a Mag 18 and use reducers at the pump connection.

I think the place you are talking about is called Reef and Rivers, I live about 2 miles away from him and I wouldn't believe anything the owner says. He sold me some expired DT by peeling the date sticker off, told me it smells fine and is still good.

 

[Reef Guy]

House: if thats so what other pump can I get with about 1800 GOH using 145 watts @ under $100

Cali: Yea, thats the guy. My gf lives one block away from them so I usually get my stuff there. But now that you tell me that I will use more caution when buying anything there. Thats what I was going to go with 1 1/4'' I shouldnt lose too much pressure that way right?

 

[cali_reef]

Originally posted by Reef Guy:
Thats what I was going to go with 1 1/4'' I shouldnt lose too much pressure that way right?

In theory, you should not lose any pressure due to larger diameter pipe if the output of the pump remains constant and the water outlet is the same size. All you are doing is provideing more room for the same amount of water to flow thru and use less friction while doing it.

 

[Reef Guy]

hey cali, you wouldnt happen to have a 3/4- 1.25 adapter would you?

 

[cali_reef]

I do, so does Lowes

 

[nanoreefer22]

LoL. Good one.

 

[Reef Guy]

actually they dont, you know where the blackmans plumbing place is on Herricks? The Lowes guy told me to try there but i got no idea where it is

 

[cali_reef]

You need a 1.25 inch union and a 1.25x 3/4 bushing, threaded if you plan to screw something in the 3/4 end. You are not going to find a reducing slip union, not even at Blackmans.

I know the Lowes close by have those pieces.

 

[Reef Guy]

Alright cali im gonna trust you and go with going with the 1.25. Well I already have a 3/4 union so all I need is the 1.25x 3/4 bushing and another part. Yea the Lowes has that one. But they are out of 2 inch caps

 

[cali_reef]

okay, you need to follow instructions or you will be making more than one trip to get what you needed. 1.25 inch union and the bushing.

Drive down another 1/4 of mile and a new HD is there, they have a lot of 2 inch stuff.

 

[Reef Guy]

Cali, you think i would lose any flow if I converted BACK into 3/4'' once i reach the top rim of the tank and go into the tank with 3 elbows

 

[cali_reef]

You will lose more flow when making turns with 3/4 inch ell vs. something larger. why do you need 3 elbows? have you looked into using some spaflex to reduce the need for hard elbows?