I just received a Mag 12 that I plan on using in conjuction with a w/d. Is there an easy way to go from 3/4 MPT to a 1 1/2 return line besides a bunch of PVC collars? Probably a stupid question, I just hate plumbing. Thanks
I was able to find a 3/4" FPT x 1.5" slip at the local Menard's. Might also want to check out a Lowe's if you have one - they seem to have the most PVC fittings out of any local store I have found. Hopefully that helps.
On a practical side, I would make the change from 3/4 to the 1.5 as close to the return as you can. I'm no physicist or expert on fluid dynamics, but if you double the size of pipe, you are going to be tryng to push about 4x the weight of water up that pipe back to your tank. It will result in head loss, making your pump a lot less efficient.
1.5" is quite a large return line on an aquarium. I usually use a 3/4" to 1" hose barb adapter. Run 1" clear vinyl to another 1" hose barb that is connected to a bulkhead (if the tank is drilled) or to rigid pvc return line(s). If your bulkhead is 1.5", you can reduce to 1" with a male adapter and slip x threaded reducer. But, the key is to use the vinyl hosing between the return pump and the tank, otherwise you get a humming noise. It's easier if pictures are involved. What size is the tank? Is it drilled or are you using an external overflow?