What do I add, how much, and in what order?
Most dosing calculators do one reading at a time, which is the easy part and the least useful. The mistakes that actually turn a pool green are mistakes of order and interaction, not arithmetic.
This runs the same ordered plan our technicians follow in the field. Enter whatever your kit gave you, leave the rest blank, and it will tell you what to add, how much, and in what sequence.
Not sure? Work it out from your dimensions.
Changes the calcium target. Plaster needs calcium in the water; vinyl and fiberglass do not.
What your test kit read
Fill in what you have. Anything you leave blank is simply left out of the plan rather than guessed at.
Waiting on a reading
0steps
Before you pour anything
Four rules that matter more than the numbers
Test before you dose, every time
A plan built on last week's reading is a guess. Drop kits are more accurate than strips, and the gap between them is wide enough to be the reason a pool is being dosed wrong all season.
Add less than you think
Every step here can be repeated and most cannot be undone. Add half, let it circulate for a few hours, re-test, then decide. Overshooting alkalinity or stabilizer is corrected by replacing water, which is expensive here.
Pump running, one at a time
Pour slowly over a return with the water moving. Chemicals added to still water sit on the floor, where they bleach plaster and do not reach the rest of the pool.
Acid and chlorine never meet
Not in the water within a few hours of each other, not in a bucket, and not on the same shelf. This is the one rule on the list where the failure mode is a hospital visit rather than a cloudy pool.
Questions we get asked
- What order should pool chemicals be added in?
- Alkalinity first, because it is the buffer that decides how far any later acid or base moves pH. Then pH. Then calcium and stabilizer, which are slow and one-way. Sanitizer last, so it is never in the water at the same moment as the acid, and so the chlorine you add works at the pH the pool now has. Correcting pH before alkalinity means correcting pH twice.
- Why does this only give me one acid dose when both my pH and alkalinity are high?
- Because muriatic acid does not lower them separately. The same pour lowers both. Charts that give you an alkalinity dose and a pH dose and expect you to add them together are the single most common reason a pool ends up in the fives. This gives you the alkalinity dose, which is the reliable half of the arithmetic, and it drags pH down with it.
- My chlorine reads normal but the pool is still going green. Why?
- Almost always stabilizer. Cyanuric acid shields chlorine from the sun, which a Texas summer makes essential, but it also binds it, so the free chlorine a pool needs rises with its stabilizer level. At 90 ppm of stabilizer a reading of 2 ppm free chlorine is doing almost nothing. Enter both above and the calculator will tell you the minimum your pool actually needs.
- Why does my pool smell strongly of chlorine?
- That smell is chloramines, which is used-up chlorine, not free chlorine. It means the pool needs more chlorine rather than less. Enter both free and total chlorine above and the difference between them is the number that matters; anything over 0.5 ppm is the trigger to shock.
- How accurate does my pool volume need to be?
- Close is enough for weekly chemistry, because doses are adjusted against a test result rather than calculated once and trusted. It matters most for stabilizer, which is the one chemical you cannot take back out without replacing water. If you are guessing, the volume calculator will get you within a few percent from three measurements.
- Can I add these all at once?
- No. One at a time, with the pump running, letting each circulate before the next. Never mix chemicals in a bucket, and never let acid and chlorine meet, in the water or in the garage. The plan above is ordered specifically so that following it top to bottom keeps them apart.
Free tools
The rest of the arithmetic
What does a pool really cost to own here?
All five lines, not just the service rate: electricity, water, chemicals, filter cleaning, and the replacement reserve nobody puts on a quote. Prices your pool both ways, doing it yourself and having it done.
Price my poolHow long should the pump run, and what is that costing?
Turns your pool's volume and your pump into a run schedule and a monthly electricity figure, then shows what a variable-speed pump would save and how long it would take to pay for itself.
Work out my run timeIs my pool leaking, or is that just a Texas summer?
The bucket test, done properly. Two measurements 24 hours apart tell you whether the water is going somewhere it should not, and what it is costing you a month if it is.
Run the bucket testHow many gallons is my pool?
Measure three things and get your volume, the surface area, and what one adjustment costs at that size. Every other calculator here starts with this number.
Measure my pool