RO filter change schedule for tricity water

The intervals printed on the box assume clean municipal water. Tricity groundwater is neither soft nor low in dissolved solids, and every filter in the chain works harder for it.

The stages and their real-world life here

• Sediment pre-filter: three to four months. It catches grit and silt, and it is the cheapest part — change it early and everything after it lasts longer.
• Carbon pre-filter: six months. Removes chlorine and organics that would damage the membrane.
• RO membrane: eighteen months to two years, if the pre-filters were kept up. Skip them and it can be a year.
• Post-carbon or taste filter: six to twelve months. This is what makes the water taste clean.
• UV lamp, if fitted: twelve months regardless of use — the tube dims before it fails.

Why the pre-filters matter most

The membrane is the expensive part. Everything before it exists to protect it. A sediment filter left in for a year lets grit through that scores the membrane, and a spent carbon filter lets chlorine through that chemically degrades it. Cheap filters changed on time are how you avoid an expensive one changed early.

Signs a change is overdue

Slower flow to the tap. A change in taste. The tank taking longer to fill. More water going to the reject line. Any of these before the scheduled date means the water is harder than average and the schedule should tighten.

Write the date on each filter housing with a marker when it is changed. It is the simplest maintenance system there is, and the one most people wish they had started.