I have looked at them before but don't really have the room for a large bucket to sit and fill up over several hours. I was buying some sort of natural filtered sea water for changes in the 29, but I'm not sure what I'm gonna do yet for the 75 as the changes will be larger. I don't think I have a source for ro/di in the area to my knowledge. I'll have to look a little harder I guess. I suppose I should start with the TDS meter and go from there.

Thanks!