MP40 or 2 MP10's on 48" tank
 

Hello the tank is 48x18x16.
Should I run 2 MP10s or a MP40?
mostly LPS and soft corals.

Mp40!

Definitely mp10s. It will give you greater choice in placement and create better flow options.

its also going to depend on your glass thickness... MP-10's are only good to 3/8" if you are more than that you will need MP-40's.

That said, I have a 120gal, 48"x24"x24" that has one MP-40, and I am added another one shortly..

I run 3 MP40s on my 77 gal, 4 foot tank. If you're going the VorTech route you may as well get at least 2, especially with the wireless option. Your flow options increase dramatically with multiple VorTechs no matter what size. Besides, on a 4 foot tank, depending on pump placement & your aquascaping, you may end up with a dead area with only a single MP40.

My 40s are placed one at each end & one at the back. They are in EcoSmart Tidal Swell Mode in Master/Slave relationship. The one on the back glass, although slaved to the master, is speed limited to a lower setting. The options are endless with multiple pumps. I had originally wanted to have an MP10 on the back glass, but with the adjustability & options available with the EcoSmart drivers, I've found the MP40 a more than viable fit at the back.