I run my reef tank off of the RO
water from walmart and have been for a year due to manure leaching into my well. All those chunks really clogged up my RO
quickly to the point where it wasn't cost effective. I don't have any big issues with it...I have a red turf algae 'issue', but it isn't overwhelming and I have it kept in check. So, I call it 'good enough'. Just make sure you are on top of things, as having a creature like a flame scallop that have such high mortality rates in our tanks lead to big issues with phosphates due to feeding them. It is a double edged sword that usually leads to disaster or, at minimum, death of the scallop and an algae issue that takes awhile to resolve.