Active Aqua 300 Reverse Osmosis System by Active Aqua. $214.44. Active Aqua - 300 Reverse Osmosis System This 3-stage reverse osmosis unit is ideal for fresh water applications, drinking and more. Comes with 1-micron sediment filtration, a carbon block for VOC reduction and a TFC membrane. Also includes quick connect fittings, a shut-off valve, a filter wrench for easy cartridge replacement, and hose bib feed adaptor. 3-year limited warranty. Made in the USA. ...