I don't argue that it can't be done at all, but for those that choose not to use RODI (overall, looking at the multible threads that pass thru here), it appears to be one of two sectors....either newbies that don't know any better, or those from the 'old school' that tend their tanks as it was done 20 years ago. Newbies, I can totally relate, unless you have been educated and still choose not to based on your cockiness, or maybe even your exceptional natural water source. But for the latter, I think that this hobby continues to bring on some of the world's most amazing advancements, one by one, and for us not to embrace this, if for no other reason than to eliminate one additional roadblock, is pure...I was about to say stupidity, but no, these people are not stupid, so I will use stubborn. Yes, stubborness...this is my honest conclusion.