reef safe alternative to gear clamps

[lastlight]

I'm currently using gear clamps on a rubber coupler to connect my pond pump to my 1.5" return plumbing. The clamps are not normally submerged but have become submerged a few times during pump shut-downs when the sump level rises. They are both now rusty and I'd like to replace them.

Anyone have any ideas? It's a 4200 gph pump so it needs to be strong still.