Test. Dose. Swim.
BlueDose is a free Android app that turns your pool or hot tub water test into exact chemical doses: how much chlorine, acid, baking soda, calcium, stabilizer or salt to add, in what order, for your volume and the products you have.
How it works
Use your usual test kit or strips and type in only what you measured: free and combined chlorine, pH, alkalinity, calcium, stabilizer (CYA), salt, borates, temperature or bromine. Everything else is prefilled from your last test.
BlueDose lists every chemical to add, in the order to add it, sized to your pool’s volume and in the units you use: fluid ounces, cups, pounds, grams or milliliters. Tap a dose to switch to the product on your shelf and see its side effects.
Tick “I added this” to record the dose in your log. A safe-to-swim countdown, a 30-minute retest reminder after acid and a weekly test reminder keep the water on track.
Features
Free chlorine, pH up or down, alkalinity, calcium, stabilizer, salt, borates and bromine, with liquid chlorine, bleach, cal-hypo, dichlor, trichlor, lithium hypochlorite, acids, soda ash, borax, baking soda and more.
Minimum, target and shock (SLAM) chlorine for every stabilizer level, and how much chlorine it takes to clear algae or combined chlorine.
A calcium saturation index (Langelier form, corrected for CYA and borates) warns when water turns corrosive or scale-forming, protecting plaster, heaters and salt cells.
Every test in one list with trend charts and target bands. Edit entries, record what you added, export to CSV or back up everything as one file.
Filter cleaning, brushing, baskets, salt cell, cover care and cartridges, with per-task reminders and sensible defaults for pools and hot tubs.
Step-by-step fixes for cloudy water, algae, chlorine smell, pH drift, high CYA, scale, stains, foam, the spa routine, opening, closing, storms, salt cells and fresh fills.
Bromine or chlorine, spa ranges, teaspoon and tablespoon doses, a soak countdown, and a drain-and-refill schedule from your tub’s size and bather load.
Fully translated, from Arabic to Vietnamese. Follow your phone’s language or pick one just for BlueDose in More → App language.
No ads, no sign-up, no analytics, no subscription. Every calculation runs on your phone, with or without a signal, and your data never leaves it.
Also included: unlimited pools and hot tubs (plaster, vinyl or fiberglass; chlorine, salt water, bromine or mineral systems), a pool volume calculator for rectangle, round, oval, kidney and free-form shapes, a water-replacement calculator for high CYA, calcium or salt, and a chemical safety sheet with the order of addition.
Screenshots
Swipe sideways to see all six. Tap a screenshot for the full-size image.
Under the hood
BlueDose doesn’t use rule-of-thumb tables. Each dose is worked out from the chemistry of the product and the water you measured, by an on-device engine covered by unit tests.
Liquid chlorine strength is read as trade percent: grams of available chlorine per 100 mL. Household bleach, labeled in weight percent, is converted to trade percent first, and solid products (cal-hypo, dichlor, trichlor, lithium hypochlorite) use their available-chlorine fraction. Raising 10,000 US gallons by 1 ppm takes 10.24 fl oz of 12.5% liquid chlorine.
Acid and base doses come from a closed-system equilibrium model of carbonate, cyanurate and borate in your measured water. Acid demand therefore rises with total alkalinity, stabilizer and borates, as it does in a real pool, instead of a fixed amount per 0.1 pH. When alkalinity is high, pH is handled by a staged alkalinity-lowering process rather than a separate acid dose.
Water balance is the calcium saturation index (CSI) in Langelier form, from pH, temperature, calcium hardness, dissolved solids (estimated from salt) and carbonate alkalinity: total alkalinity minus the part contributed by cyanurate and borate. BlueDose aims for −0.3 to +0.2 and tells you which level to change first.
When raising slow-moving levels (alkalinity, calcium, stabilizer), BlueDose aims for the low quarter of the ideal range so you use less chemical. Implausibly large doses are flagged so you can double-check the volume and readings. Doses are estimates: follow the product label, add one chemical at a time, and retest.
| Product and change | Amount |
|---|---|
| Liquid chlorine 12.5%+1 ppm free chlorine | 10.24 fl oz303 mL |
| Baking soda+10 ppm total alkalinity | 1.4 lb636 g |
| Calcium chloride 77%+10 ppm calcium hardness | 1.2 lb545 g |
| Stabilizer (cyanuric acid)+10 ppm CYA | 13.3 oz379 g |
| Pool salt+1,000 ppm salt | 83 lb37.9 kg |
| Muriatic acid 31.45%−10 ppm total alkalinity | 25.6 fl oz756 mL |
BlueDose scales these to your volume and to the product strength you pick, then converts to the units you use.
FAQ
Yes. BlueDose is free to download and use. There are no ads, no subscription and no in-app purchases, and nothing is locked: every calculator, chart, guide and reminder is included.
No. There is no sign-up, login or email address to give. BlueDose works offline, so it calculates every dose even at the equipment pad with no signal.
Twelve chlorine products (liquid chlorine 12.5% and 10%; bleach 8.25%, 7.5% and 6%; cal-hypo 73%, 65%, 53% and 48%; dichlor 56%; trichlor 90%; lithium hypochlorite 35%), muriatic acid in four strengths and dry acid, soda ash, borax or aeration to raise pH, baking soda, calcium chloride flakes or anhydrous, granular or liquid stabilizer, pool salt, borax or boric acid for borates, dichlor, liquid chlorine, bleach or non-chlorine shock (MPS) to raise bromine, and sodium thiosulfate to neutralize chlorine. Tap any dose to switch products and see its side effects, such as cal-hypo raising calcium or dichlor raising stabilizer.
Yes. Hot-tub mode uses spa ranges, bromine or chlorine, and doses small enough to measure in teaspoons and tablespoons. It adds a drain-and-refill countdown worked out from the tub’s volume and how many people use it, plus filter and cover reminders. You can keep unlimited pools and hot tubs in the app.
Each pool can follow the Trouble Free Pool (TFP) method, common industry ranges, or your own targets. With TFP, the free chlorine target follows the stabilizer (CYA) level: at 40 ppm CYA, keep FC at 5–7 ppm and never below 3, with a shock (SLAM) level of 16 ppm; pH is 7.6–7.8 and alkalinity 60–80 ppm. Industry ranges use a fixed 2–4 ppm FC, pH 7.4–7.6, alkalinity 80–120 ppm and calcium 200–400 ppm for plaster. BlueDose is not affiliated with Trouble Free Pool.
Yes. Each pool or hot tub can use US units (gallons, fluid ounces, cups, pounds, °F) or metric units (liters, milliliters, grams, kilograms, °C). The volume calculator handles rectangle, round, oval, kidney and free-form pools in either system.
Doses are calculated from the chemistry of each product (available chlorine, molar mass and purity) and, for pH, from an equilibrium model of your water, so they are in line with established pool calculators. In practice, accuracy depends most on your pool volume and your test kit. BlueDose flags implausibly large doses and aims for the low end of the range when raising slow-moving levels. Doses are estimates: follow the product label, add one chemical at a time, and retest.
Only on your phone, in BlueDose’s private storage. BlueDose has no servers, no analytics and no ads, and it sends nothing to Swift Softs. If Android device backup is turned on, your data is included in your own Google account backup. You can also export your log as a CSV file or share a backup file yourself. Details are in the privacy policy.
Languages
The whole app, including dose notes and guides, is translated. Choose the language in More → App language or follow your phone.
BlueDose is free on Google Play for Android 8.0 and later. No ads, no account, and it works offline.
Get it onGoogle Play