Indeed, where the RO reject more than three times the volume of water to a usable volume of water, ultrafiltration or microfiltration not reject at all! 0 waste !
The ultrafiltration or microfiltration filter less than compounds that reverse osmosis , but some compounds are good at keeping to the reef aquarium, such as calcium ! Resin anti nitrates finished the circuit and ensures quality water for your aquarium.
The material is generally more expensive than RO to purchase, but it can make significant water savings !