Actually none of them work perfectly to filter germs, ppm etc. Combine system like RO/UV/de-ionizer together can show great performance to get healthy water, weather it for home or garden.
hydrologicsystems.com filter brand. Who build highly engineered water filter for customer.
They have all types of filtration system for commercial or residential uses. They have RO UV sterilizer kits to enhance filter performance too. You can chek their website for more information.