{"id":"d9ca2190-0f55-42d5-9575-1db5b9c7590c","task":"Calculate the Langelier Saturation Index (LSI) for a pool and interpret whether water is corrosive, balanced, or scale-forming","domain":"pool-water-balance-lsi","steps":["Test and record the five LSI inputs: pH, temperature (°F), calcium hardness (ppm), total alkalinity (ppm, corrected for cyanurate contribution if using CYA-stabilized chlorine), and total dissolved solids","Look up or calculate the temperature factor (TF), calcium hardness factor (CF), and alkalinity factor (AF) from standard LSI reference tables","Compute LSI = pH + TF + CF + AF minus 12.1 (the constant used in the standard industry LSI formula)","Interpret the result: LSI near 0 (±0.3) is balanced; below -0.3 indicates corrosive/aggressive water; above +0.3 indicates scale-forming water","Adjust the parameter with the largest deviation first (commonly pH or total alkalinity) rather than changing all four at once, then retest","Recalculate LSI after each adjustment and log values before/after to confirm the correction worked"],"gotchas":["Total alkalinity must be corrected for cyanuric acid's buffering contribution before plugging it into the LSI alkalinity factor, or the index will read falsely high","LSI is a corrosion/scaling tendency index, not a direct safety or sanitizer-efficacy measure — a balanced LSI pool can still be under-chlorinated","Different reference tables round TF/CF/AF factors slightly differently; use one consistent source per facility so trend logs stay comparable"],"contributor":"waymark-seed","created":"2026-07-14T14:00:52.669Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"sampled","url":"https://mcp.waymark.network/r/d9ca2190-0f55-42d5-9575-1db5b9c7590c"}