Pool and hot tub care
Clear water,
every season.
Tell us your numbers. Pool Almanac tells you exactly what to add, in the amounts you actually buy, then remembers every test and warns you before problems start.
- Free for one pool
- No card
- Your data stays yours: export anytime
How it works
Test. Do. Relax.
Test
Log it in 30 seconds
Big steppers you can use with wet hands. Drops, strips or a digital reader: enter the numbers you see.
Do
Exact doses, in order
What to add, how much of the product you own, and what to wait for. Tap a step to mark it done and log it.
Relax
Hear about it first
Test reminders, and weather alerts when rain or a heat wave is about to move your chlorine.
Why it works
Four promises, kept on every test.
A knowledgeable neighbour, not a salesman. Everything below is how the app behaves today.
Honest doses.
Amounts in what you actually buy (“7 cups of 10% liquid chlorine, about ½ of a 1-gal jug”), from standard CYA-based targets, never a brand's shopping list. Tap any step to see the math.Show the math FC 3 → 6 ppm: 3 ppm × 15,000 gal ÷ 781.8 = 57.6 fl oz
You pour: 7 cups of 10% liquid chlorine, about ½ of a 1-gal jug
Remembers your pool.
Every test, treatment, photo and setting in one place. Ask a question and the answer uses your history, your weather and your equipment, not a guess.Ahead of problems.
Heavy rain tonight? Heat wave this week? Chlorine trending down? You hear about it before the water turns.- Heavy rain tonight
- Heat wave this week
- Chlorine trending down
Yours, privately.
Export everything, anytime, free. Our AI runs on our own servers: your pool data isn't sent to outside AI companies.Export every reading as CSV, free, on every plan
Ask anything
A coach that has read every test you've logged.
Ask in plain words. The answer draws on your pool's history, equipment and local weather, and every amount comes from the same tested engine as your plan. The coach explains the numbers; it never invents them.
Runs on our own servers. Your data stays with us.
Why does my pH keep going up?
Coach
Your pH has risen about 0.3 a week since you switched to salt. That's typical for salt pools: the cell's bubbles push pH up.
Tonight, add 2 cups of 31.45% muriatic acid in front of a return jet to bring pH from 7.9 to 7.5. I'll remind you to retest in 30 minutes.
- Your last 6 tests
- Salt cell since June
- Your pool size
The almanac part
A calendar for your water, not just a calculator.
Pools change with the seasons. Pool Almanac keeps the checklists, watches the forecast, and adjusts the plan as the weather turns.
Spring
Opening day, in order.
An opening checklist for your pool: uncover, top up, run the pump, then balance in the right order, with doses for your volume.
Heavy rain tonight. Test FC in the morning.
Summer
Rain tonight? You’ll know.
Alerts for heavy rain and heat before they move your chlorine, and a pump plan that runs longer in hot weeks and slower the rest.
81%less electricity at 1,500 RPM than full speed, same turnoverEstimate for a 1.5 HP variable-speed pump, affinity lawsPlan yours
Fall
Closing without guesswork.
A closing checklist and winter chemistry for pools that close, and a lighter routine for pools that stay open all year.
Hot tubs too
Small water, small doses.
Bromine or chlorine, a hot tub needs tablespoons, not cups. Raising chlorine from 1 to 5 ppm in a 300-gallon tub takes 1½ fl oz (3 tbsp) of liquid chlorine. The math is the same engine, scaled down honestly.
Hot tub careThe accuracy promise
Every dose is checked against 50 reference cases on every release.
Each case is worked by hand from published pool chemistry, and the release stops if the engine disagrees with any of them. Every case also runs through an independent calculator, and each difference is shown with its reason.
See every case and the mathPricing
Free for one pool.
Premium is $39.99 a year (save 33%) or $4.99 a month. Every new account gets 14 days of Premium first, no card.
Founding members: $29.99 a year for the first 1,000 annual subscribers, through January 31, 2027. Locked in while you stay subscribed.
See plans and terms| Feature | Free | Premium |
|---|---|---|
| Exact doses, every calculator, history and export | ||
| AI coach questions | 5 a month | Unlimited |
| Smart weather and trend alerts | ||
| Pools and hot tubs | 1 | Unlimited |
Questions
Asked by pool owners.
Is it really free?
Yes. One pool or hot tub, every calculator, exact doses, reminders, unlimited history and export are free, with no time limit. New accounts also get 14 days of Premium with no card; after that the account stays on Free and keeps everything. The free plan includes 5 coach questions a month.
Which test kits does it work with?
Any kit that gives you numbers: drop-count kits, test strips or a digital reader. You enter what you read. Drop-count kits are the most precise for chlorine and CYA, but you don't need one to start.
Does it handle salt pools?
Yes. Salt pools get their own targets (stabilizer around 60 to 90 ppm and the chlorine range a salt cell can hold) and plan steps for the cell itself, such as raising or lowering its output.
What about hot tubs?
Bromine and chlorine hot tubs are covered, with doses sized for a few hundred gallons: tablespoons, not cups. The water check and calculators handle hot tubs today.
Is my data private?
Your pool data is yours. Export everything, anytime, free. Pool Almanac's AI runs on our own servers, so your pool data isn't sent to outside AI companies.
Does it work offline?
Logging a test works without a signal and syncs when you're back online, so you can log poolside where the Wi-Fi doesn't reach.
Does it work in metric, or in Australia?
Yes. Switch to litres and metric doses at any time. There's also an Australian site with A$ prices and local product names like pool acid and stabiliser.
How is this different from ChatGPT?
ChatGPT guesses at the math and forgets your pool the moment you close the tab. Pool Almanac checks every dose with a tested chemistry engine, remembers every reading, watches your weather, and reminds you when it's time to test.
Your water, explained in a minute.
Put in the numbers from your last test. Pool Almanac tells you what to add tonight, in the amounts you buy.