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Pool calculators

Dose, acid and the saturation index, worked the way a route tech works them. Nothing is stored and there is no signup.

Chlorine dose calculator

Pounds of 73 percent cal hypo to bring free chlorine up to where you want it.

Acid dose calculator

Muriatic acid to bring pH down, adjusted for total alkalinity. An estimate: add half, retest, add the rest.

Saturation index

The Langelier index: whether the water will eat the plaster or scale it up. Near zero is balanced.

In Everglow

Readings on every stop, and the index worked out for you.

Everglow logs chemical readings on each visit of a weekly route, and works out the saturation index in the app with the same formula as this page, so a trend shows before the water turns.

Start free for 14 days Open the pool demo

More calculators for service businesses →

A demo pool company’s route on a phone: the next seven days of stops, in order.
Matanzas Pool Care, a demo company.

About these numbers

Where the math comes from

Should I add the whole dose at once?

No. Add half, then retest. Every dose here is a calculation, not a measurement. Water responds to what is actually in it, so the safe habit is half the dose, circulate, retest.

How is the chlorine dose worked out?

Assumes 73 percent calcium hypochlorite, where a pound in 10,000 gallons raises free chlorine about 8.7 ppm. Different product, different number.

What does the saturation index mean?

pH plus a temperature factor, plus a calcium factor, plus an alkalinity factor, minus a constant for dissolved solids. Below minus 0.3 the water is corrosive; above plus 0.3 it scales.

Should I record each reading?

A calculator answers today. A route needs the history: what this pool read last week, and the week before. That is the Chemistry tab →