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How to Backwash a Master Filter

The 10-minute chore that saves your home plumbing from muddy destruction.

The Mechanics of Backwashing

Over 14 days, the heavy sand and silica sitting inside your large outdoor cylinder trap pounds of raw mud and rust. If you don't flush it out, your shower pressure will drop to a trickle. Backwashing simply reverses the flow of water inside the tank—pushing water from the bottom upwards—violently fluidizing the sand bed and blasting the trapped dirt out through a dedicated drain hose.

The Standard 3-Step Process

Most outdoor FRP tanks feature a thick plastic 'multiport valve' handle on top. Turn off any booster pumps, and follow this exact sequence:

  1. Step 1: BACKWASH. Turn the handle firmly to 'Backwash'. Water will begin erupting from the drain hose. It will look like pure tarik (thick brown mud). Let it run for 3 to 5 minutes until the water runs completely, 100% clear.
  2. Step 2: RINSE. Turn the handle to 'Rinse' (sometimes called Fast Rinse). This pushes water downwards to re-compact the sand bed firmly so sand doesn't escape into your house. Run this for 1 minute.
  3. Step 3: FILTER. Turn the handle back to 'Filter' (or In-Service). Your home is now fully protected again.

How Often Do I Do This?

In areas with stable municipal water, backwash every 2 weeks. However, if your utility company recently shut off the water for pipe repairs (a scheduled water cut), the moment the water comes back online, the pipes will blast massive amounts of concentrated rust. You MUST backwash your filter immediately after any city water disruption before turning on your indoor taps.