One test, every dose — how this calculator works
Most pool chemical calculators handle one chemical at a time, which quietly creates a problem: doses interact. Acid that fixes your pH also pulls down your alkalinity. Trichlor that raises chlorine also raises CYA — permanently. Cal-hypo brings calcium along with every shock. This dashboard computes the whole test as one system, using the same industry-standard formulas as Taylor's watergram and the Trouble Free Pool method, so every card shows not just the dose but what that dose does to the rest of your water.
How to use it
1. Test your water — strips work, a drop-count kit is meaningfully more accurate for FC and TA. 2. Enter every reading you have — the more you enter, the more the dashboard can tell you (pH, TA and CH together unlock the water-balance card). 3. Work down the cards, one chemical at a time. Your pool volume, sanitizer type and chemical preferences are remembered on this device, so next week's test is a 30-second job.
What each reading controls
| Reading | What it controls | Typical range |
|---|---|---|
| FC — free chlorine | Sanitation. The only number that kills algae and pathogens. | Depends on CYA (see below) |
| pH | Comfort and corrosion — eye sting, etched plaster, cloudy water. | 7.2–7.8 |
| TA — total alkalinity | pH stability. Low TA lets pH swing; high TA drags it upward. | 60–90 ppm |
| CYA — stabilizer | Sunscreen for chlorine. Too little burns FC off; too much blunts it. | 30–50 ppm (60–80 with SWG) |
| CH — calcium hardness | Scale vs. etching on plaster, tile and heat exchangers. | 250–450 ppm |
| Salt | Feedstock for a salt chlorine generator. | 2,700–3,600 ppm (SWG pools) |
Stabilizer binds most of your chlorine in reserve — protective, but it means a pool at CYA 90 needs far more total FC to have the same active sanitizing power as a pool at CYA 30. That's why this dashboard asks for CYA before giving an FC target, and why "1–3 ppm" pool-store advice fails stabilized pools. The chlorine/CYA relationship guide covers the chemistry in full.
The order to add chemicals
Chlorine first if FC is at or near zero — an unsanitized pool is the only true emergency on the list. Otherwise: adjust pH next (most other chemistry behaves better in range), then alkalinity, then stabilizer and calcium, then salt. One chemical at a time, pump running, 30–60 minutes between doses, and never let concentrated acid and chlorine meet — in the water, in a bucket, or in storage.
Every dose is derived from molecular weights and available-chlorine fractions — not copied tables — and cross-checked against PoolMath's published doses in an automated test suite. The dose math needs your pool's volume to be right: if you've never measured it properly, start with the pool volume calculator — it takes two minutes and every tool here remembers the result.