they recently made some small improvements to the design, like thicker filter floss on both ends and slightly larger washers that seem to have resolved a lot of te issues with turbidity.
I actually use this thing for all my tanks...maybe 200 gallons in total and daisy chain 2 of them when the tds is up from the tap, which is rarely.
Est this at about 5 gallons and hour...lol
The replacement cartridges are
http://www.jlaquatics.com/product/ro...Cartridge.html