Mag 5 return question

[titan04]

I have a mag 5 for return for my 30G cube that will return to a 1in bulkhead....

Should I run 1/2" up to the bulkhead and open it up then? or run 1" right to the mag 5 with an adapter... wondering about the effects with 4ft of head... I heard somewhere there was better flow with double sized than the outlet? I can go either way easier but before I start cutting pvc want to make sure which way is better

 

[RichConley]

The bigger pipe you use, the better.

 

[titan04]

Then I will stick to the 1" so all my fittings and pipes are the same.

Thanks.

 

[miatawnt2b]

I would actually be a bit worried about the mag loosing flow with the extra head pressure generated by pusing water up a 1" pipe. I'd stick to using 1/2", minimize the elbows, use 45's instead of 90's, and open up to 1" at the bulkhead. The mag pumps aren't very efficient when it comes to head pressure.

-J

 

[samsfishnchips]

titan04,

next time, tried the Head Loss Calculator it might be helpful

http://reefcentral.com/calc/hlc2.php

RichConley's advice is correct, bigger pipe is better always if the person wants to achieve max flow of water

but in some cases someone will prefer to take a small hit of flow loss for a better pluming job, using smaller lines

miatawnt2b, a kind advice
stick with what you know, your statement is false, and indeed the makers recommend lines of 1.5" in order to achieve advertised flow ratings, and if thats not possible, just increase to the next size, ex

.5" pump outlet, use .75" lines
1" pump outlet, use 1.25" lines and so on


smaller lines, more friction, less flow
smaller output tip, more velocity of jet of water

sam

 

[tekknoschtev]

<a href=showthread.php?s=&postid=6910361#post6910361 target=_blank>Originally posted</a> by miatawnt2b
I would actually be a bit worried about the mag loosing flow with the extra head pressure generated by pusing water up a 1" pipe. I'd stick to using 1/2", minimize the elbows, use 45's instead of 90's, and open up to 1" at the bulkhead. The mag pumps aren't very efficient when it comes to head pressure.

-J

They tell you to double the output size for maximum efficiency....

There was a discussion a bit ago about how the added "weight" of the water in the pipe isnt seen as resistance from the pumps standpoint, though I havent been able to search for it so I couldnt get a direct link but basically, the pump doesnt feel that resistance as much as you'd think.

 

[titan04]

Thanks for the link nunez1980, just what I was looking for. I could see the smaller being more constrictive and possible putting more head pressure than a slightly larger volume.

Anyway sticking with the 1in that I had already bought to match the bulkheads... First impluse buy that has worked out that and the phosban reactor

 

[RichConley]

<a href=showthread.php?s=&postid=6910367#post6910367 target=_blank>Originally posted</a> by nunez1980
bigger pipe is better always if the person wants to achieve max flow of water

but in some cases someone will prefer to take a small hit of flow loss for a better pluming job, using smaller lines

Theres also the "Is it worth it" effect. Going from half inch to 1 inch pipes on a mag 5 may double the flow you get out of it. Going from 1 inch to 2" may only give you another 20% increase in flow, but its going to cost you 10 times as much in pipe fittings. 1" valves are about $3. 2" ones are about $15.

So getting 300 gph is worht it, when 320 would cost you another $100 in plumbing.

If you need to run smaller pipes, a pressure rated pump would be a better option.

 

[titan04]

It was more of a general question... I didn't want to go to the max flow... just if 1" provided more than 1/2" I wanted to use it since my bulkhead was already 1" but didn't mind 1/2" if it was better....

I already had 1" fittings but when the return out of the pump was 1/2" I was wondering which was better... instant adapt there or adapt it basically at the end of the run for the water...

I am going to go with the 1" so all my pipes are the same size and already have true union valves... I think that is worth the little extra price for if they ever need cleaned... don't have to cut pipe that way and then can run a long pipe cleaner through the rest if I have to do maintainence on those.

Thanks all for the input and help...