New to marine: setting up my 26G bowfront

[Acipenser]

So I decided to try out marine, my plan is to keep it a simple as possible for now. So it will be a fowlr tank with a shallow sand bed, so far I have bought a Koralia nano 425 gph power head, an instant ocean hydrometer, some live sand ( even though Iv'e read that live sand is useless) and the salt. Wondering if I can use any of my fresh water HOB filters to move water around or should I just buy another koralia nano ?

I plan on adding the live rock in the next couple of days then waiting a few weeks while I research on fish and make sure everything is stable.