Technical Knowledge Base

MembraneIntelligence.

Industrial RO performance data, supply chain strategies, and drop-in replacement guides designed for engineers.

Does Reverse Osmosis Remove Chlorine? What Actually Happens at the Membrane

Does reverse osmosis remove chlorine? Not the way you'd hope. Free chlorine destroys polyamide RO membranes — here's what actually takes it out and why it matters.

Enviro Membranes Engineering Team

Jul 20, 2026 8 min read

Water Quality

The Hardest City Water in America, Ranked — Straight From the Utilities' Own Reports

We read the official water quality reports of 30+ cities across the US, Mexico and Chile and ranked the hardest, saltiest municipal water on the continent. Every number is from the utility itself.

Enviro Membranes Engineering Team

Jul 17, 2026 7 min read

Water Quality

Total Dissolved Solids: What the Number Actually Tells You About Your RO System

Total dissolved solids is estimated from conductivity, not weighed. What a TDS reading hides, what RO rejection specs mean, and how permeate TDS creep signals membrane failure.

Enviro Membranes Engineering Team

Jul 17, 2026 8 min read

RO Membranes

Silt Density Index: The Feedwater Test That Decides Whether Your RO Membranes Foul

What silt density index measures, why RO manufacturers cap SDI15 at 5, how to run the test right, and what it misses. A field guide for commercial RO.

Enviro Membranes Engineering Team

Jul 15, 2026 8 min read

Water Chemistry

Why Tap Water Turns Brown, and What Your Filter Actually Does About It

Brown tap water is almost always iron. What causes it, why a utility can be compliant while your water stains, and what a cartridge filter does and doesn't remove.

Enviro Membranes Engineering Team

Jul 15, 2026 7 min read

RO Membranes

RO Membrane Replacement Cost: What a Changeout Actually Runs in 2026

Real 2026 prices for 8040 and 4040 RO membrane replacement: element costs by brand, labor and downtime, cleaning economics, and when a changeout pays.

Enviro Membranes Engineering Team

Jul 13, 2026 7 min read

Reverse Osmosis

Reverse Osmosis Antiscalant: How the Dose Gets Set, and How the Program Fails

How reverse osmosis antiscalant dosing gets set: FilmTec LSI limits, matching chemistry to scale type, and the overdose failure most plants misdiagnose.

Enviro Membranes Engineering Team

Jul 10, 2026 8 min read

Reverse Osmosis

Commercial RO System Repair: Diagnose the Real Fault Before You Replace Anything

A symptom-by-symptom guide to commercial reverse osmosis system repair: low flow, high TDS, rising pressure drop, and telling a fixable fault from a dead membrane.

Enviro Membranes Engineering Team

Jul 8, 2026 7 min read

Maintenance

Reverse Osmosis System Maintenance: The Schedule That Actually Keeps a Commercial System Running

A commercial reverse osmosis system maintenance schedule built on normalized data, not the calendar: cartridge, CIP, antiscalant, and replacement intervals that hold.

Enviro Membranes Engineering Team

Jul 6, 2026 9 min read

Operations

How to Clean a Commercial RO Membrane (So the Cleaning Actually Holds)

RO membrane cleaning done right: when to trigger a CIP, which chemicals match which foulant, and the sequence and temperature limits that make it hold.

Enviro Membranes Engineering Team

Jul 3, 2026 7 min read

Commercial RO

Brackish Water Reverse Osmosis: Why Feed Chemistry Sets Your Recovery Limit

Brackish water reverse osmosis design hinges on feed chemistry, not TDS alone. Real membrane specs, recovery limits, scaling risks, and system costs.

Enviro Membranes Engineering Team

Jul 2, 2026 6 min read

Membrane ComparisonFeatured

LG NanoH2O BW 400 R G2 vs DuPont FilmTec BW30 PRO-400: Which Belongs in Your System?

LG's TFN technology gives the BW 400 R G2 a real rejection advantage over FilmTec's BW30 PRO-400 — 99.8% vs. 99.6% stabilized, 500 GPD more flow. Whether that difference matters in your system depends on feed TDS and permeate target. A spec-by-spec breakdown of where to use each.

Enviro Membranes Engineering Team

Jul 2, 2026 6 min read