So I live in Sweden and here, we do have really clean water that we drink. But I am really confused on if I should get a RODI system as we have really clean water and i've heard of some people here keeping corals without using one. I am new to the saltie hobby and just want to know if it's needed here as we have really clean and stable water or if there is some other reason for using one that makes it a necessity. So what should I do? Any fellow Sweden that know if I need them or not?
