DE NORA TETRA potable water filters

One of the most trusted names in drinking water filters.


In gravity filters, the underdrain is one of the most important components contributing to overall system performance and operation — whether a new filter design or retrofitting of an existing filter. De Nora Water Technologies offer DE NORA TETRA™ LP Blocks dual parallel lateral underdrain and the DE NORA TETRA U Blocks  underdrain for drinking water and desalination pre-treatment applications.



DE NORA TETRA™ LP and U block drinking water filter underdrains both offer advantages for operators including:

  • Low headloss
  • Easy installation
  • No moving parts
  • Even backwash distribution
  • Reduced backwash water
  • Lower operating cost
  • High resistance to uplift from the filter floor


Additional features for water filters with LP Block underdrains:

  • Efficient media cleaning at reduced operating costs - excellent distribution of backwash air/water
  • Reduced installation costs – wide profile design requires fewer laterals than most DPL designs, thus fewer joints, grout, and installation time
  • Lower cost of filter box - low height profile of LP Block allows for reduction of filter box depth
  • Easy maintenance, long life and simple installation
  • Simplifies retrofit of existing shallow filters, accommodates various air and water backwash schemes, and allows for greater media depth resulting in better filtration performance
  • Anchor-Rite® and GroutGrip features minimize buoyancy and offer increased adhesion to filter floor
  • Media retention plates simplify media replacement, allow for greater media depth, and prevent media from entering underdrain.

DE NORA TETRA™ LP Block DPL Filter Underdrain


DE NORA TETRA™ LP Block Installation


De Nora Water Technologies