reefsahoy how did you arrive at a number of 13????
You cannot accurately predict what a properly working system will do without first knowing what their tap water TDS is! Also there is no safe maximum TDS anywhere in the US, its not an enforceable limit set by the EPA or any public entity that I am aware of. 250 is actually the national average for TDS with lots of places exceeding 1000 and very few under 100 and some as low as 50 like Atlanta, you can't put a number to what someone can expect from RO. If you are getting 13 down from 200 thats only marginal at best , it should be only 4. 13 is a 93.5% rejection rate when it should be 98%.
Simmlink, what you can expect is a 96 to 98% reduction in you tap water TDS whatever it may be. In my case the tap TDS is 782 and my RO only is 5.8, much less than 13. RO only does most of the work and is excellent for drinking water but you really need a final polishing with DI for reef quality water. In most cases its only another $30 or so to get an RO/DI over an RO only, of if you do end up buying an RO only places like
www.thefilterguys.biz have add on DI kits for less than $40 complete.
My advice to you is avoid e-bay RO or especially RO/DI units as well as most hardware or big box store varieties, they just don't produce the same quality of water and in some cases the components are not worth what you will pay for the unit.
Look at vendors here on RC for some great systems starting at about $149 for a very good RO/DI that will produce reef quality water and its not that much more to add a drinking water kit. I would get the Reef RO/DI and add the drinking kit instead of the drinking water kit and add the DI as the filters are usually better quality in a reef system and will make your DI resin last much longer.
