Pros and cons of this setup (first time sump)

[boboyo]

Wondering if this would create a nitrate factory. Bottom is a marine pure block which cycled for 3 weeks in my current aquarium and I was thinking adding these little pellet things I got with my new setup. Any thoughts? It’s kind of a low flow area and I plan on growing cheato on top.

 

[P-Dub]

I think you'll be just fine.