Leaving an active residual in the water.

Not treating it once at a point.

So the supply stays protected downstream.

Through storage and distribution.

And out to the outlets.

In pH range and by-products.

Chlorine weakens as pH rises.

Dioxide works across a wider range.

Produces fewer chlorinated by-products.

And is far better against biofilm.

Because organisms shelter inside it.

From a residual that only reaches the water.

So a system can test clean.

While harbouring growth in the pipe wall.

Dioxide penetrates it far better.

Because it cannot be stored.

It is made as it is used.

From precursor chemicals.

Which makes the equipment more involved.

And the installation more expensive.

The monitoring, not the dosing.

A dose setting is only an input.

The residual at the far end is the outcome.

Only that says whether it is working.

Dosing without monitoring is an assumption.

Because demand varies through the day.

A fixed rate over-doses at low flow.

And under-doses at high.

Flow-proportional or residual feedback.

Keeps the concentration in range.

In most jurisdictions, yes.

Competence, chemical approvals.

And safe storage and handling.

All part of the installation.

Rather than adjacent to it.