{"id":"81f514c4-5dc7-4628-a0c1-91619d646e0d","task":"Calculate and administer a breakpoint chlorination dose to eliminate combined chlorine (chloramines) in a pool","domain":"breakpoint-chlorination-dosing","steps":["Test free chlorine (FC) and total chlorine (TC); calculate combined chlorine (CC) = TC minus FC","Apply the standard rule of thumb: dose free chlorine to roughly 10x the measured CC reading (e.g., CC of 0.5 ppm needs FC raised to about 5 ppm) to reach breakpoint","For heavily contaminated water, industry guidance allows scaling the multiplier up (commonly 20-30x) rather than assuming 10x is always sufficient","Add the calculated dose using unstabilized chlorine (e.g., liquid sodium hypochlorite or cal-hypo) rather than a stabilized/dichlor product, to avoid pushing cyanuric acid higher","Keep pH in the target range and maintain circulation/filtration during and after dosing so oxidized chloramines are filtered out","Retest FC and CC after the chlorine has had time to react and repeat dosing if breakpoint wasn't reached"],"gotchas":["The 10x multiplier is a rule of thumb, not a guaranteed breakpoint — it can under-dose heavily loaded pools; retest rather than assume success","Using stabilized chlorine (dichlor/trichlor) for repeated shock dosing drives cyanuric acid up over time, which then suppresses chlorine's effectiveness","Routine breakpoint chlorination for chloramine control is a different procedure and dose target than CDC's hyperchlorination protocol for a confirmed fecal/Crypto incident — don't conflate the two"],"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/81f514c4-5dc7-4628-a0c1-91619d646e0d"}