poolchemistrycalc

Raise salt

Into 21,100 gal of water, add

52.74lb

We assume a target of 2,700 ppm. That is this site's own assumption, not a figure from a code or a manufacturer: no regulation we have read states a salt level at all, and the only fetched limit that touches a salt pool is Maryland's ceiling of 3,000 ppm of total dissolved solids. Read the number your own chlorinator asks for off the cell or its manual and type it in — every figure below follows it. This is a ceiling on total dissolved solids in a salt water pool, not a target for salt. Salt is most of what it measures, so a salt level above it puts the water over the limit on its own. Salt from 2,400 ppm to 2,700 ppm.

Salt on one scale: the band up to 3,000, the ideal band none stated, the reading now at 2,400 ppm, and an arrow to 2,700 ppm carrying 52.74 lb. reads now 2,400 ppm target 2,700 ppm no higher 3,000 52.74 lb +300 ppm with Salt

Your pool

feet, the long side
feet
inches of water, not wall height
inches of water
what your kit reads
where you want it
per cent, off the bag
pounds in one bag

The answer, the drawings, every reading and every table on this page are worked for the values in these fields, and worked again as you type. The questions further down are answered for the example this page was published with.

In steps, if you would rather

One dose split five ways. Add a step, run the pump, and test again before the next.
To reach Add Total added
2,460 ppm 10.55 lb 10.55 lb
2,520 ppm 10.55 lb 21.10 lb
2,580 ppm 10.55 lb 31.64 lb
2,640 ppm 10.55 lb 42.19 lb
2,700 ppm 10.55 lb 52.74 lb

Where the band comes from

Source Range
COMAR 10.17.01.45 A(5)
salt water pool 		up to 3,000 ppm

Pool and spa rules are adopted and amended state by state, and most of the ranges here are written for public pools. Confirm every figure against the code your jurisdiction has adopted and against your own product label.

What people ask

How much salt does a 21,100 gal pool need?
52.74 lb to take the reading from 2,400 ppm to 2,700 ppm in 21,100 gal. We assume a target of 2,700 ppm. That is this site's own assumption, not a figure from a code or a manufacturer: no regulation we have read states a salt level at all, and the only fetched limit that touches a salt pool is Maryland's ceiling of 3,000 ppm of total dissolved solids. Read the number your own chlorinator asks for off the cell or its manual and type it in — every figure below follows it.
How many 40 lb bags of salt do I need?
2, which is 52.74 lb rounded up to the next whole 40 lb bag. We assume a target of 2,700 ppm. That is this site's own assumption, not a figure from a code or a manufacturer: no regulation we have read states a salt level at all, and the only fetched limit that touches a salt pool is Maryland's ceiling of 3,000 ppm of total dissolved solids. Read the number your own chlorinator asks for off the cell or its manual and type it in — every figure below follows it.

Other adjustments

Updated September 2026

Sources and dates

Ranges are quoted from the code named beside them, product strengths from the manufacturer's own product page, each retrieved on the date shown.