You may not be able to reach 2200MHz as that is a lot of stress on the memory controller. You are just going to have to experiment with the settings Dark Mantis suggested - your kit and components will give a different result than someone else with the exact same components. Just luck of the draw!
If you cannot get 2200MHz stable, you can always work your way up from 1600-1800MHz and increase the frequency until it becomes unstable, then decrease it back to the highest stable frequency. I doubt you will even notice a difference, and you may even be able to tighten timings below rated values.
Changing the command rate from 1N (sometimes shown as 1T) to 2N (2T) may help get increase stability also.
As long as your mobo and cpu allow, the water cooling setup should be able to cope with 4.5GHz
I have a 480mm rad, the EK HF and MCP655 and I hover around 60C load on all cores at 4GHz, which is what I keep it at for 24/7 usage.
Good luck!