I am looking to purchase a RO system for drinking and reef. The systems at airwaterice.com looks good but I wasn't sure which one would be best for drinking & reef. The two I am comparing is Dual Home/Reef & Typhoon III models. I only need the RO/DI water for tank top-off so I don't need a lot of RO/DI water production. Is the water quality any different between these units? Is the DI cutt-off & membrane flush essential in a ro system? The Dule H/R doesn't come with these but is does come with a 3.5 gal tank ($69 value). Also, is it easy to switch from RO and RO/DI water? I figure that the tank would store the RO water and you will some how be able to get the RO/DI water directly from the filter. Is that right? I am trying to stay around $200. The Typhoon III would be an easy choice if the tank came with it.