Tankless Water Purifier vs Traditional Water Purifier: What's the Difference? While a tankless water purifier filters water just when needed and does not store it, a conventional water purifier has an integrated tank to pre-filter and store the water for dispensing. Tankless types offer fast fresh filtered water, conserve space, and remove the possibility of bacterial growth in stored water. Original Source: https://hydroflux84.wixstudio.com/singapore/post/tankless-water-purifier-vs-traditional-water-purifier-what-s-the-difference