Have an reverse osmosis unit that you don’t feel has enough firepower to provide clean water to make water changes for your marine or reef aquarium? Well, take that three stage filter and pile on the accessories. Adding more stages to your RO system is easy and affordable, for the most part. Deionization chambers can be added, as can booster pumps and high volume TFC membranes to really clean the water and do so more efficiently. And the best part is that most, if not all of the parts are universal, so you don’t have to worry about sticking to the brand you originally purchased.