Lets talk RO systems...

I use a RO200 stealth by Hydrologic, I haven't changed the filters in over a year for the water still coming out at 007 ppm the pH good, but prefilter looks kinda almost strating to look dirty, what should I do? My filter almost never stops I run it in and day... unfortunately my water city water is 400 ppms and I am organic mostly...

Output quality determines when to change the membrane. Changing the prefilters every 6-12 months will prolong membrane life.

I use a cheap eBay portable RO that gets up to about 20ppm after a year...New filters are 20 bucks for a complete set...Lemme see if I can find a link...I use the 100 gallon per day model, so sometimes it takes a while to fill the fresh water reservoirs...But you know...planning and regular water changes take care of that.

Pretty sure it['s this one...Sometimes I cheap out and have to buy a better item, and sometimes I cheap out and the item actually works...This time it worked out pretty well I guess...but going the cheap route is always a gamble
http://www.ebay.com/itm/250-Longer-Ultra-Portable-RO-DI-water-filter-100GPD-0PPM-2-5-Reverse-Osmosis-/380797498333?pt=LH_DefaultDomain_0&hash=item58a94cb3dd

I also use it for my saltwater reef tanks for freshwater to top off, and my corals are very sensitive to crappy water quality...But they thrive with it.