How much stabilizer for a 30,000 gallon pool

In a 30,000 gallon pool, 2.5 lb (1.1 kg) of stabilizer granules raises cyanuric acid (CYA) by 10 ppm. Taking fresh water from 0 to 40 ppm needs 10 lb (4.6 kg). Liquid stabilizer is weaker by weight: 0.94 gal per 10 ppm.

Stabilizer doses for 30,000 gallons

30,000 US gallons (114 m³).
ChangeGranules (99%)Liquid (25%)
Raise 10 ppm2.5 lb0.94 gal
Raise 20 ppm5.1 lb1.9 gal
Raise 30 ppm7.6 lb2.8 gal
Raise 40 ppm10 lb3.8 gal
Raise 50 ppm13 lb4.7 gal
CYA 40 → 70 (salt pool)7.6 lb2.8 gal

Run it with your numbers

gal

Not sure? Work out your pool volume.

ppm
ppm

30 to 50 for manual chlorine; 60 to 80 with a salt cell.

%

Add

10lb

of Stabilizer granules (cyanuric acid 99%)

162 oz4.6 kg

Raises CYA from 0 ppm to 40 ppm in 30,000 gal.

  • This is a large change. Add it in stages and retest between them.
  • Also raises cyanuric acid (stabilizer). It only comes down by replacing water.
  • Put the granules in a sock in the skimmer basket or in front of a return. Do not backwash for a week.
  • Stabilizer takes several days to dissolve and register on a test. Do not add more in the meantime.
  • At CYA 40 your free chlorine minimum becomes 3 ppm and the target 6 ppm.
  • Adding too much is hard to undo: only draining lowers CYA. If unsure, add three quarters, wait a week and retest.

Check the product label. Strengths vary by brand, so enter the % printed on yours. Add one chemical at a time, into the water, and never mix chemicals.

Save this test and get reminded when it is time to retest.

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About stabilizer

Granules dissolve slowly. Put them in a sock or the skimmer basket with the pump running, and don’t backwash for a week. CYA takes several days to show fully on a test, so don’t top it up before then.

Overshooting is the expensive mistake: nothing you can add lowers CYA, only replacing water does. If you are unsure of your volume, add three quarters of the dose, wait a week and retest.

Manual chlorine pools usually run CYA 30 to 50. Salt water pools run 60 to 80, because the cell makes chlorine all day. Your chlorine target rises with CYA: see the FC/CYA calculator.

Dosing a 30,000 gallon pool

In a 30,000 gallon pool doses run to gallons and bags, so pour or broadcast them while walking along the deep end or in front of several returns rather than in one spot. Larger pools take longer to mix: give the pump at least an hour before you retest.

Questions

How much stabilizer for a 30,000 gallon pool?

2.5 lb of granular cyanuric acid per 10 ppm. From 0 to 40 ppm: 10 lb.

How long does stabilizer take to dissolve?

Granules can take several days to a week to dissolve and register on a test. Wait a week before adding more.

How do I lower stabilizer if I add too much?

Only by replacing water. The drain and refill calculator shows how much.