IO regular vs IO RC!

[mrhasan]

I am currently using IO regular but since I have started adding pretty corals (no SPS; they are just way too challenging for me and I like things that moves with flow ), I was thinking whether I should start using RC. My current system does have a 440ppm calc but I don't know about magnesium since I don't have its testkit.

So should I stick to regular one or get a RC for 20 bucks more.

Alongside, even if I do change to RC, can I mix the salts or should I do a big water change with RC to replace the regular mix in the system?

Thanks