Pipe diameter and pump for saltwater mixing station?

[SteveG_inDC]

I am building a mixing station for a 240 gallon display with a 100 gallon sump. The two containers are side-by-side 55g drums. The saltwater storage tank will be about 3 feet away (horizontal run) from the sump, so I don't need to push very far.

Questions:
1. What pipe diameter should I use for my plumbing?
2. What pump should I use? I have a Mag 7, Mag 9, and two Mag 12s lying around. Not sure if I can use one of those externally. I was going to use one of the Mag 12s as a return and one of the smaller mag drives for my skimmer.

 

[Jeto2004]

All depends on how quickly you want to pump you water for you water changes. 3/4 or 1 inch would be more than enough. My understanding is that the mag drive pumps can be used as submersible or in-line pumps.

 

[SteveG_inDC]

Any other opinions here? It makes sense that I should consider pump first and then size the plumbing accordingly. I guess what I need to know is how strong a pump do you really need for mixing saltwater?

Before having mixing stations I just threw the largest mag drive I had into a plastic bin, with a bigger pump meaning faster mixing.

Also, my Mag-9 just randomly went bad on me. Every time I plug it in it trips the GFCI and I can't figure out why. If i plug it into a non-GFCI protected outlet it doesn't turn on.

So it looks like I need to buy a new external pump. How do you choose? I do not need to push against any head pressure other than the height of a 55 gallon drum. My sump is going to be a few feet horizontally from the mixing station.

I need the pump to be reliable and ok with being turned off and on a lot. I don't think I need it to be controllable,

 

[IKD]

I’ve seen a number of folks using Pan World pumps. Jebao pumps are also an option. If you want to get a redundant option, you can buy the exact pump you use for your display tank return so if that fails you can pull the one from your mixing station until you get a replacement.

 

[Futuretotm]

Jebao dcp 15000 (a second one is my main return)

3/4 inch piping, however had to reduce as the jebao had 1.5” outlet (smallest ones in the box)