Mag 12 Plumbing Question

[nbgen12]

What is the best size pvc for plumbing with a Mag 12?

I'm building a new 40 breeder sump for my 75g reef and plan on using the mag 12 pump as a return since my powerheads don't provide enough flow. The sump will be sitting alongside my 75g DT since I do not have space for the skimmer underneath my stand. I plan on feeding my fuge chamber from the return, and also splitting the return so I have the return in each corner of the aquarium. Since the sump is at the side of the DT, water needs to flow a little further distance than usual.

As of now, I bought 1" PVC to use from the mag 12, and reduce to a .75" PVC for the fuge pipe and also for the PVC being used for the return lines going up and over into the corners of the DT. Will this restrict the flow too much? Or would it be better to use 1.25" from the mag 12, and reduce to the 1" PVC for the fuge and corner returns?

Hopefully my description makes enough sense....I'm not exactly up to snuff on plumbing terms.

[sirreal63]

Danner recommends 1-1/2" plumbing to get the rated flow from the pump. The question will be can your drain system handle the flow? That Mag is a horrible choice for a return pump, it's high wattage is a heater that runs 24/7. It is usually a bad idea to try and get main tank flow from a return pump.

[Joel_155]

I had a mag12 as my return in my old tank and the line needs to be at 1.5 inches to get max flow. However be prepared as you tank will sound like Niagara falls if there is more than a few inches of fall space in your overflow box.

[kclewis]

I have ran mag pumps for 10+ years. They are work horses. Just make a manifold off of your pump and run other items like reactors off of it. I have never ever had a heat issue with mine. I currently run an 18 for my 90. It feeds the fuge, gfo, carbon, and bio pellet reactor. All of this on top of return to the tank. Restricting flow on them just creates more head pressure.

[nbgen12]

I hear you on the high wattage 24/7 deal for sure. The reason I decided to go with the mag 12 was because it was not overly expensive upfront, the flow I will get through the sump will match the flow on my skimmer pump making it efficient, and the fact that I can get that sump flow while being able to feed the fuge also. My overflow is rated for 900gph, so I figure if I stay below 800gph I should be safe. The extra flow in the DT is just a plus since I needed something more anyway. But like I said, being able to do this and get the right flow rate through the sump to match my skimmer pump is the main goal. I'm looking to get as close to 700 gph as I can.

[d2mini]

I have ran mag pumps for 10+ years. They are work horses. Just make a manifold off of your pump and run other items like reactors off of it. I have never ever had a heat issue with mine. I currently run an 18 for my 90. It feeds the fuge, gfo, carbon, and bio pellet reactor. All of this on top of return to the tank. Restricting flow on them just creates more head pressure.

It's well known that they are heat generators and they pull a lot of juice.
There are MUCH better options for return pumps out there.

[nbgen12]

I do understand the power requirements and the heat put-out....but I've purchased the pump already. I'm not about to sell a new pump for 60% of the price to turn around and get an eheim 1262 for $210 which i dont think provide the flow i need for the fuge, manifold, and return lines (2 of them).

Does my plumbing setup/gph target sound like they are line with each other? I won't be running anything off the manifold at first....

[sirreal63]

Use the right size plumbing and it will do what you want.

[nbgen12]

Use the right size plumbing and it will do what you want.

Well I get that much:banghead:

the reason i am asking is because i have no clue so far if i have the right size plumbing to do what i want.

[sirreal63]

Use 1-1/2" and it will give you the most you can expect from the pump.

[kclewis]

Did you get your pump running?

[nbgen12]

Not yet, it will probably be a month before i have time to get everything setup and rollin. I gotta take back some of the plumbing and switch to the 1.5" pipe and figure out where im going from there with the plumbing design.

[Izshocker]

1.5" pipe, says so right in the manual.

[nbgen12]

Appreciate the help