Plumbing question - Mag18 3/4" MPT to 1.5" PVC. How to best plumb?

[gweston]

I am ready to start plumbing my new basement fish/sump room for soon to be installed tanks.
I bought most of the plumbing necessary, but I have one remaining thing to work out.

Question:

How can I best connect a Mag18 pump with a 3/4" MPT fitting to 1.5" PVC for the return?

While at the hardware store, I found some adapters to do this, but it was a nasty looking mishmash of multiple reducers. Thoughts? I will eventually replace this pump with something better, but it is a new/unused pump, and I have it. I'll likely get something a bit heftier later, especially if I plumb yet another tank upstairs (THE WIFE SAID YES THIS MORNING! MUHUHUA!)

This is basically how it is going to look, excuse my rather crude ascii example.

<pump><3/4"MPT> --<convert-size>--<1.5" union> ---------<T>-----<T>-----<T>-----<BallV><1">
<BallV> <BallV> <BallV>
<1"> <1"> <1">

*mm it looks fine when I edit it, but it doesn't save right. Oh well. You get the idea.

Off each ball valve it converts down to 1" return lines (either barb fittings, or pvc pipe) that will go to a mix of tanks. 125g long display, 40breeder display, 20g Frag/sump-return, extra line for future use. Some may convert from a single 1" down to multiple 3/4" returns at the tank.

Thanks in advance!

 

[JohnK]

The plumbing sounds OK, but have you run the head loss numbers yet? You may not get much at all ouf of that mag18, it's shut off is @16'

 

[nicksgt]

I agree with john I have a mag 18 coming up from my basement to my 75 and its barely enough flow and my ceilngs arent that high.

 

[FinsUp!]

+1 to what others have said, especially with all those T's and ball valves. I have a mag 12 in my sump under the stand of my 58, so it's only got a little under 5' of vertical rise, but I have an outlet for the refugium and 4 outlets in the tank. It's just enough, but if I were to do an SPS dominant tank, I'd probably need to add a powerhead.

 

[gweston]

The sump is going to be behind the wall right behind the display tanks. Frag tank a few feet away from the sump.

I recently finished a basement man-cave with a fish room behind it. So from the pump to the tank, it will mostly be a horizontal run over a rather short distance. Even then, there will be some head loss with the plumbing itself.. a couple 90 degree turns and such. I am thinking I will need to up the size of the pump though... as honestly, I'd like to have a lot of flow through the 125. The tank has a beananimal style overflow with full sized 1.5" drains. Recently built.

The problem. I'm not ready to fork over another $400 for a new super-pump, though I'd LOVE to have one. But, my Mag18 is NEW and unused. I may be able to sell it and put the funds towards a larger pump. I will seriously think about this and see if I can convince the wife if I can expand the tank budget by a little bit *duck and hide!*.

I MAY put another tank up one floor -someday-. So I should probably take that into consideration when getting a replacement pump. OR. I could stick to the Mag for the existing tanks, and add a second pump in the future to handle the upstairs tank. If it ever comes to fruition. Heck. Its taken me well over a year to get to the point I am right now, so I don't yet want to add yet another tank too soon.


Oh.. and. To convert from 3/4" to 1.5". Should I just chain up multiple PVC reducers? Such as 3/4" to 1", then 1" to 1.5" or something? I haven't seen any 3/4" to 1.5" adapters. It just seems nasty to chain up multiple reducers, but if that is what it takes!.

 

[JohnK]

Ahh, I misread, saw "basement" and thought you were saying basement sump for a tank upstairs.

The mag should work OK for your application, but it's still a mag. I was particularly quick to suggest not using it because you said it's new and that had me thinking that you might be able to return it. It'll do the job for now and will make a good water change pump when you've gotten fed up with it and bought a real return pump


And yes, you can chain up multiple reducers if you can't find one that goes from .75 right to 1.5". Not as pretty, but perfectly functional.

as for the future plans, if you try to use one pump to feed tanks on two different floors you may run into some tuning issues trying to keep the flow balanced the way you want. The ideal set up would probably use dedicated pumps for the different floors IMO.

Also keep in mind, mag pumps don't match up very well to a lot of other pumps when you compare the max flow rates, you really have to look at the flow charts. Mag pumps are dismal at handling head pressure. For example compare a mak 4 and a mag 18 at say 12' of head.

Edit, searching for examples;
I couldn't find the flow chart for a mak 4, but here's how an iwaki 55 compares to a mag18

iwaki 55, 1080 gph at 0 head, @840 gph at 12' of head
Mag 18, 1800 gph at 0 head, 450 gph at 12'

 

[MikeG]

I know in my area I can find a much better selection of reducers at Lowes compared to HD and the mom and pop plumbing supply stores. They normally carry everything from 2-3" down to 1/2" in a single reducer.

 

[gweston]

Thanks guys. Started on the plumbing tonight. Found the parts at Lowes. HD's selection was dismal by comparison. I was able to get the 3/4" FPT up to 1.5" quite easily with a couple parts. I even picked up parts (thinking ahead) to plumb in a better future pump with a 1" outlet. It'll be an easy swap out with a disconnect. Can even keep the pieces around so the mag can be a backup.