HELP!- Return Line Size

Ok, I'm getting my return line plumbing today and need to know weather or not I should get 3/4" pipe or 1"the pipe and what the benefits/negatives are for each one.

Is it harder on the pump for the largr diameter pipe or not etc.

I have a Mag 9.5 which has 3/4" MPT and my return to the tank is 3/4"MPT bulkhead to a 3/4" to 1/2" reducing locline wye.

I will also wye off the return to feed the fuge, thiss will have a ball valve on it.

There will be about 5' of head so the pump should put out 750gph.

Given this should I T off (edit X off or +... whichever way you're holding it LOL) the return w/3 ball valves and have the unused one to feed a future reactor?

Thanks in advance for any help.

 

I dont mean to be offensive but this is really hard to picture what is going on. You asked a lot of questions so to answer everything a picture or diagram would be very helpful to us to help you out.

 

The return is on the right


Plan to use this


or this (is supposed to be a cross "+" fitting)


With ball valves @ each open end to feed the fuge, return and a reactor if you think the pump can do all three

if it can't then will use a "Y"

 

So is 3/4" pipe good enough or should I do 1" and bring it back down to 3/4" at the return.

Does the larger pipe diameter put too much back pressure on the pump, will it slow the water velocity down at the return?

 

Larger diameter has less velocity and will reduce friction losses. It does not "increase back pressure" or effect the pump at all.

What you want to do is use larger discharge pipe and then when you branch off go to smaller to distribute everything well.

Teeing off the return to feed the fuge sort of just recircs pods through the pump... maybe multiple times. Plus it is "clean" water after the skimmer. It would be best to split your drain and feed the fuge with raw tank water. Not sure you can do that or not or what your setup is.

If you look close at you Mag documentation, it gives head values with much larger pipe diameter than 3/4. It needs the 3/4" outlet to perform properly, after that, you could put 2" pipe on there and it would not matter... except bigger pipe and valves cost more and line loc is most common in 3/4". So use 1" and then branch and reduce to line lock, other things.

 

as far as the return line go from 3/8 to 1 inch and when you need to reduce it back down to go back into the tank reduce it there, 1 inch is what I used. just took and threaded a cupling right from the top of the pump to make it fit 1'' pipe and reduced back down to 3/8 at the top to put back into the locline.

 

Thanks guys.