Poolbook: Pool & Spa Chemistry

Poolbook is a pool chemistry calculator and water test log for your pool or hot tub. Type in your free chlorine and pH and it tells you how much of your own chlorine, acid or other product to add. Unlimited test history, no account, and it works offline.

POOL WATER TEST LOG
• Free chlorine and pH up front: two numbers, then Save
• More readings when you need them: combined chlorine, total alkalinity, calcium hardness, stabilizer (CYA), salt, bromine, borates and water temperature
• Every reading with a target is marked low, in range or high
• Unlimited tests and history, free. Edit or delete any test

POOL CHLORINE CALCULATOR: WHAT TO ADD
• "What to add": the dose of your own product, in US or metric units
• For pH it's a starting dose: add it, run the pump for 30 minutes and test again
• Liquid chlorine, cal-hypo, dichlor, trichlor, muriatic acid, dry acid, soda ash, baking soda, calcium chloride, stabilizer and pool salt, with the strength and price you set
• Tap "Added" and it goes into your log
• Chlorine targets based on your stabilizer (CYA), editable, plus water balance (LSI)
• Combined chlorine too high? The dose takes your chlorine up to shock level
• Too much CYA, calcium or salt? It tells you how much water to replace

POOL CALCULATORS, FREE
• Dose calculator for chlorine, pH, alkalinity, calcium hardness, stabilizer and salt
• Pool volume for rectangular, round and oval pools
• Drain and refill: the percentage and volume of water to change
• You never have to watch an ad to see a result

SALTWATER POOLS AND HOT TUBS
• Salt chlorinator pools get their own targets, salt doses and a salt cell task
• Hot tubs and spas: chlorine or bromine, spa targets and spa filter tasks
• Calcium hardness target set by your surface: plaster, vinyl or fiberglass

POOL MAINTENANCE REMINDERS
• Test the water, empty skimmer and pump baskets, brush and vacuum, backwash the filter, check the salt cell and run a full test
• For spas: rinse and deep-clean the filter, drain and refill, clean the cover
• Add your own tasks
• One notification on the day a task is due

CHARTS AND YOUR DATA
• Free chlorine and pH over time with the target band, free
• Back up and restore your log, free
• Export tests and additions to CSV, free
• US units (gallons, °F) or metric (liters, °C), and your currency
• No account. Your pool data is never sent to us

PREMIUM: 7-DAY FREE TRIAL FOR NEW SUBSCRIBERS (YEARLY OR MONTHLY)
• Yearly or monthly subscription, or one payment for life
• Cancel anytime in Google Play
• No ads
• Unlimited pools and spas (the free plan keeps one)
• Every chart: each reading with its target band, LSI over time, this season vs. last and daily chlorine loss
• Chemical spending by month, season and product

Amounts are a guide: follow the label, add products one at a time with the pump running, never mix them, and leave 30 minutes between acid and chlorine.

Privacy policy: https://poolbook.alekla.com/privacy/

Recent changes:
We now remind you 5 days before your subscription renews, so you can cancel in time if you want to. Numbers and prices now follow your region's format. Plus small fixes.