How to Choose a Laboratory Water Purification System: 2026 Buying Guide

Lab water ranges from general deionized water to Type I ultrapure reagent water. Choosing the right system comes down to four decisions: the water grade you need, which purification modules, how you'll dispense, and capacity. This guide maps each to the Yamato Scientific WA/WB/WC/WG, Auto-Still®, WE, and WH systems.

1. What water grade do you need?

• Type I ultrapure (18.2 MΩ·cm) — for HPLC, ICP-MS, molecular biology, and analytical chemistry. The WA/WB/WC/WG systems deliver it at 2.5 LPM on demand.
• Distilled + deionized — for general lab use, media, and glassware. The Auto-Still® WG-205/253/1013 distill and deionize.
• Deionized (Type I / A4) — the RO+DI WE-200, or the compact WH cartridge systems for point-of-use DI.

2. Which purification modules? (Type I systems)

The WA/WB/WC/WG platform is modular — add only what your application requires:

System	Modules	TOC	Best for
WA	DI cartridges + 0.2 µm filter	< 15 ppb	General Type I reagent water
WB	+ Ultrafiltration	< 15 ppb	Pyrogen-free, nuclease-free water
WC	+ UV oxidation	< 5 ppb	Organic & analytical chemistry
WG	+ UV + UF	< 5 ppb	Genetics & biological work

Add a TOC monitor (the "T" configurations: WC-UVT, WG-UVUFT) when you need to verify and document organic purity in real time.

3. Benchtop or remote dispense?

• Benchtop / wall-mount (B) — the system and dispense point are together; simplest installation.
• Remote dispense (R) — a separate dispense head lets you draw water at the point of use while the unit sits elsewhere. Order 301 for 120V/60 Hz or 311 for 220V/50 Hz.

4. Capacity (distillation systems)

For distilled water, size by daily demand: WG-205 (~1.5 L/h, 20 L tank), WG-253 (~1.5 L/h, 30 L tank, expandable cartridges), or WG-1013 (~5 L/h, 100 L tank) for high-volume labs.

Frequently Asked Questions

What is Type I ultrapure water?

Type I water has 18.2 MΩ·cm resistivity with very low TOC and <1 cfu/ml bacteria — required for sensitive analytical and molecular work. The Yamato WA/WB/WC/WG systems produce it on demand at 2.5 LPM.

What's the difference between WA, WB, WC, and WG?

They're a modular family: WA is the base (DI + filter), WB adds ultrafiltration (pyrogen/nuclease-free), WC adds UV oxidation (lower TOC, organic chemistry), and WG combines UV + UF for genetics and biological work. "T" versions add a TOC monitor.

Do I need UV or ultrafiltration?

Add UV (WC) for the lowest TOC in organic and analytical chemistry; add ultrafiltration (WB) for pyrogen-free, nuclease-free water; choose WG when you need both, as in genetics and cell biology.

When should I choose a distillation (Auto-Still) system?

Choose the WG-205/253/1013 Auto-Still® when you want both distilled and deionized water for general lab use, media preparation, and glassware — sized from ~1.5 L/h (20–30 L tank) to ~5 L/h (100 L tank).

Source: Yamato Scientific water-purification documentation. LabSupplies.com is an authorized Yamato dealer — genuine units, full manufacturer warranty, in stock, ships from USA.