Nice I have a DCT4000 pump waiting to be installed. I just working out my design for new piping, which I am going to try and include a manifold for my BRS reactors.
Good job! DC pumps are great if only they make one for high head pressure I will switch in a heart beat. The ones working with pressure are those made in Germany and they cost thousands of dollars.
For your manifold I would have a union right at the output of the pump so you can swap the pump out without touching anything else. I have mine setup like that and it's easy to train someone else.
Bit the Jebao Bullet
After seeing Herb's (@HerbieK ) tank today with, what someone counted....12 powerheads....I really questioned the mere two MP40's I have in my 90. In talking to @Sunny, he talked me into a Jebao WP25. Well, I doubled that, and just ordered two for under 100 clams! That's less than what I paid for two wet side replacements for my MP's. This is the first Jebao purchase for me, so curious to see how they'll hold up. Hopefully better than the Koralia Evolution powerheads I purchased (four of them), that lasted less than a year.