Great tank, and well thought out first rate.
As to the Deltec pumps they are nice lots of flow for low watts but i had to pull three of my 180 as if not cleaned every 6 months they would jam, and just get hot. I have heard mixed reports from no problems at all to complete pump failure due to bearing corrosion.
The bearing needs to run wet, and I am not sure the original pump body was designed for saltwater use.
I hope all work ok and you do not have a problem.
I replaced mine with iwakis, and these have proved more reliable