Water hammer from my check valve

[ReefJunkie]

Thanks for the advice Steve, I tried both of the solutions to no avail.
I did install a ball valve after the check valve (was going to anyway to adjust flow) and I also installed a 90 after the check valve but it did not affect it at all. The ball valve works but does not help for unexpected power outages or pump failure. Any other suggestions? Anyone? What type of check valves do others use?