I am first to invent motor and impeller assembly with magnetic attachment together, and 20 + companies copied and sold my invention. Tunze was first to copy they invented and patented separate magnet holder, motor and impeller. I FILED 2006
Yes vortech aquarium pump invented a non-submersible motor. Too expensive and did not warranty when they got wet and damaged when they first came out. My invention was right after the vortech propeller pump, by a few weeks.
To be honest as a reef enthusiast I would probably pass but only because I like having adjustable flow rates without putting my hands in the tank. I also kind of like not having the electricity in the tank. Less heat transfer to the water column and less risk of I jury to livestock or myself.
If you could add some control ability that's reliable and not noisy while keeping it affordable I think you'd open up a much bigger market for your pump.
Currently I think the only ones giving the Vortechs a run for their money are the Jebao pumps. But any warranty repairs or replacement needs to be sent back to Asia which makes it pretty much not worth it as far as I know.
I wish you the best with your pump though and appreciate your enthusiasm.