Solutions by situation
High TDS water — the one case where the meter earned its keep
The problem
High TDS is the one condition a handheld meter genuinely diagnoses, and it is a real problem: water above roughly 1,000 ppm tastes salty or bitter, and BIS's acceptable limit is 500 mg/L.
The complication is what high TDS does to the economics. Recovery falls as feed TDS rises — from around 65% on clean municipal feed to 35% on brackish water — so a household on 1,500 ppm wastes considerably more water per litre produced than one on 400 ppm.
And a high reading still says nothing about what is dissolved. Salty and bitter point at different ions, and the parameters with health limits are invisible to the meter regardless of how high it reads.
What this situation actually needs
Requirements first, in the order they matter. Note that several of these are not products.
Dissolved solids reduction
The palatability problem, and the reason for the purchase.
RO membrane matched to the measured feed TDS
Adequate feed pressure
Rejection and recovery both depend on pressure, and both fall as feed TDS rises.
Booster pump sized for the membrane and the feed
Reject water management
At high TDS, recovery can fall to a third, so reject volume becomes substantial.
Reject plumbed to a storage tank for washing and flushing
Pre-treatment where hardness or iron is present
High-TDS groundwater frequently carries both, and both shorten membrane life.
Softener or iron removal ahead of the RO, sized to the measured figures
Rejection verification
On high feed TDS, a small drop in rejection produces a large rise in product TDS.
Feed and product TDS measured at installation and quarterly
The specification
Written as a specification rather than a product name, deliberately. A specification survives a model being discontinued and can be taken to any shop; a product recommendation expires.
| Attribute | Target | Why |
|---|---|---|
| Membrane | Standard domestic to ~2,000 ppm; brackish-water membrane above | Beyond the design envelope, recovery collapses and membrane life shortens sharply |
| Pump | Booster sized to the membrane's required feed pressure | Under-pressurised membranes reject poorly regardless of their rating |
| Recovery | Expect 35–55% at high feed TDS | Plan the reject volume rather than discovering it on the water bill |
| Storage | 8–12 litres for a family of four | Production rate falls at high feed TDS, so buffer matters more |
| Monitoring | Own a TDS meter and check quarterly | The only instrument that detects falling rejection |
What to avoid
In every one of these situations there is a purchase that looks obviously right and is wrong.
A water softener bought to fix salty water
A softener exchanges calcium and magnesium for sodium. Hardness goes, the salt stays, and more sodium is added — so the taste often gets worse. This is one of the most expensive mis-sales in Indian water treatment.
Standard domestic RO on genuinely brackish feed
Above about 2,000 ppm the unit is outside its design envelope. Recovery collapses, waste rises steeply and the membrane works hard for a short life.
Plumbing the reject line to the drain
At 35% recovery you are discarding roughly two litres for every one produced. A tank for washing and flushing costs a length of pipe.
Assuming high TDS is the whole story
Nitrate, fluoride and arsenic can all be present alongside it, and none of them show on the meter that prompted the purchase.
Frequently asked questions
Which purifier is best for 1500 TDS water?
Why does my RO waste more water than my neighbour's?
Can a water softener reduce TDS?
Budget bands are indicative Indian market ranges for planning, last reviewed 2026-08-08. Where this page recommends a test before a purchase, that ordering is deliberate — the specification depends on the result, and a recommendation made without one is a guess wearing a table.