[melev]

You'll need to use larger plumbing that the threads on that pump to deal with the head pressure. A Mag 18 has 1" threads. I would use 1.5" to 2" pipe from the pump all the way up to the tank, and reduce it down right at the bulkhead.

Be sure to put a union on the pump, and then connect the plumbing to the union. That way you can unscrew the union when you need to remove the pump for cleaning.