Customer Water Chemistry Handover

Purpose

Between your visits the pool is dosed by somebody who is not you. This procedure guarantees the shop knows what the customer is adding, decides in writing what they may add, sizes that permission so the worst single mistake is recoverable rather than a closure, and gates all of it on the state of the customer's own chemical store.

Two failures follow from skipping it and only one is chemistry. A correction does not hold, because the habit that raised the number keeps running after you sold the fix. And the garage, where tablets sit above an open acid jug, is an ignition and a gas event your visit is the only trained set of eyes on.

Scope

Covers the written handover left with a residential or small semi-commercial customer: reconstructing what has been added, setting the permission tier, gating on the chemical store, the instruction card, the never-mix teaching, the numeric call-us triggers, and next-visit verification.

It does not cover shop dosing arithmetic (shock dosing and acid handling SOPs), the on-arrival response to an out-of-range reading, or stabilizer targets and drain fractions (cyanuric acid and partial drain SOPs). Product on your own truck is the transport SOP.

Roles and responsibilities

The three tiers, and the gate on each

Procedure

1. Reconstruct what has been added since the last visit, in containers. Ask which product, how much, on which days, and ask to see the containers. Accept when each product is identified by label name and EPA registration number, with its weekly amount in their own container units. Wrong is "just tabs sometimes": count empties and have them point at the level on the jug. Hazard is the containers, so never open, decant or sniff one to identify it - an unlabeled jug beside pool chemicals may be acid, hypochlorite, or a mixture already off-gassing.

2. Test the pool and reconcile the readings against those additions. Accept when free chlorine, pH, total alkalinity, cyanuric acid, and salt on a salt pool are recorded with the time and each sits where the stated additions plus your last dose predict. Wrong is readings filed with no additions beside them, which is how a stabilizer climb gets blamed on fill water for three seasons. Stop rule: a gap the additions cannot explain is an unreported addition, so say so and write no card against a history you know is incomplete. Hazard is reagent handling: no mouth pipetting, keep DPD and phenol red off skin.

3. Set the tier from the table above and write the reason with it. Top-up only is the default and its product is liquid sodium hypochlorite, not tablets, cal hypo or acid: the whole permitted amount dumped at once moves free chlorine a couple of parts per million, while the same volume of acid burns plaster and makes gas if it meets hypochlorite. Accept when tier, date and reason are on the ticket and said aloud. Wrong is defaulting to self-dose because the customer asked; capability is demonstrated at step 5. Stop rule: a pool entering a dilution, algae recovery or plaster startup goes to no-dose whoever the customer is, and the service manager makes that call. Hazard: none at this step.

4. Walk the chemical store with the customer and gate the handover on what you find. Accept when every container is labeled and closed, oxidizers (tablets, dichlor, cal hypo) are separated from acid and from each other by a physical barrier, nothing sits on the floor where it floods or overhead where it falls, and the store is latched out of a child's reach. Wrong is a split cal hypo bag above an open tablet bucket with granules on the lid. Stop rule: an unlabeled, swollen or leaking container, tablets carrying a foreign granule or oil, or any sign two products have met means no card that day, nothing moved, nothing on your truck. Hazard is why this step exists: trichlor contaminated with cal hypo, oil, organic material or water can ignite with no flame, and acid meeting hypochlorite makes chlorine gas. If anything fumes or smells sharply of bleach in a closed space, everyone leaves, the door is opened from outside, nobody re-enters, and the call is the fire department - and the smell easing is never an all-clear, because chlorine deadens the sense of smell at injurious concentrations.

5. Teach the three never-mix rules and get them repeated back unprompted. Never combine two pool products in any bucket, jug, floater or skimmer; always add product to water, never water to product; one product per session with the pump running and nothing else that day. Accept when the customer says all three back without being fed the words. Wrong is nodding, which is agreement rather than recall. Stop rule: a customer who cannot repeat them goes to no-dose that day and gets the card next visit. Hazard is the demonstration, so use clean water and an empty bucket, never a real acid or hypochlorite pour.

6. Write the card: one product, one maximum, one method, one wait, and the numeric triggers. Accept when it names the product by label name and registration number, states the maximum single amount for THIS pool in their own container units, carries the wait before swimming transcribed off the label on their jug, and carries a free chlorine floor computed for this pool's stabilizer plus a pH band and a clarity test they can run (main drain visible from the deck). That floor is about 7.5 percent of the cyanuric acid reading, per the ratio in current pool chemistry guidance, computed here rather than carried from another pool. One line says the label governs anything on the card: these are registered pesticides, and use inconsistent with the labeling is a violation. Wrong is a rate per 10,000 gallons for the customer to scale, or "call if it looks off". Stop rule: no maximum in their own container units, no card; and in their words, a strong chlorine smell at the water is low free chlorine, so it is a call rather than a reason to wait. Hazard is the pour, so the card says deep end, pump running, never into a skimmer, never into a floater holding anything else, always product into water.

7. Remove what the tier does not permit, restore the sanitation path, and re-latch what you opened. Accept when removed product is recorded by name and quantity, the feeder or floater is left with its setting written down and a working sanitizer source in the pool, and the store you opened at step 4 is closed and latched as found or better. Wrong is pulling tablets from a feeder and leaving no sanitation at all, which is a green pool by the weekend. Stop rule: never remove tablets you flagged as contaminated at step 4, which stay in place for household hazardous waste collection. Hazard is transport, so anything you take rides segregated, upright and restrained per the transport SOP.

8. Get the card acknowledged, leave a copy at the pool, and verify it next visit. Accept when the customer has acknowledged it, one copy is with them, one is on the job record, and the next work order carries the card's numbers. Wrong is a card handed over and never checked, which decays into a suggestion inside a month. Stop rule: readings next visit that do not match the permitted maximum drop the tier a level, and the service manager makes that call. Hazard: none, it is paperwork, and it is the step that makes the other seven hold.

The record this produces

• Arrival: products being added, by label name, registration number and weekly quantity in the customer's units.
• Readings: free chlorine, pH, total alkalinity, cyanuric acid, salt where applicable, with times and the reconciliation note.
• Tier and store check: tier, date, reason, who decided it; store pass or fail with photographs of any failure.
• Card: product, maximum, method, label wait time, chlorine floor, pH band, acknowledgement.
• Removals: what left, what stayed, feeder setting as left.

Worked pass: a tablet habit, stabilizer at 95 ppm, and a store that fails

Residential plaster pool, 15,000 gallons, outdoor, no automation, weekly route.

Step 1. Three 3 in trichlor tablets a week into the skimmer plus "a splash" of acid. Tablets are 8 oz each, so the habit is 1.5 lb per week. The acid is muriatic at 31 percent off the jug label, and the customer points at a level reading as about one cup per addition.

Step 2. Free chlorine 2.4 ppm, pH 7.3, total alkalinity 70 ppm, cyanuric acid 95 ppm. May's visit recorded cyanuric acid at 40 ppm and this is 14 weeks later, so the rise is 95 minus 40, which is 55 ppm over 14 weeks, or 3.9 ppm per week. The tablet habit explains it. The chlorine floor at this stabilizer is 95 times 0.075, which is 7.1 ppm, against a measured 2.4, so the pool sits 4.7 ppm below its own floor while the customer believes they chlorinate it weekly.

Step 3. The pool is going into a dilution, so the tier is no-dose, decided by the service manager on the phone from the deck.

Step 4 FAILS. Garage shelf: an open tablet bucket with a scoop resting in it, a cal hypo bag above with a split corner and granules on the tablet bucket rim, and an unlabeled jug of cloudy liquid beside both. Two acceptance conditions fail (containers closed, oxidizers separated) and the granules are foreign material in the tablets. Stop rule taken: no card, nothing moved, nothing loaded. The overhead door was opened from outside and left open, the customer was told not to open, scoop, close or move any of the three, and the household hazardous waste route went on the ticket with photographs.

Follow-up, four days later. Tablets closed in their original bucket in a latched cabinet, acid across the garage, unlabeled jug collected. Steps 5 to 8 ran. The card: liquid sodium hypochlorite at 10 percent in the one gallon jug they own, maximum one quart per addition, deep end with the pump running, wait before swimming transcribed off that jug's label. The quart is a ceiling, not a dose. At the field rate for 10 percent trade strength, one gallon in 10,000 gallons raises free chlorine about 10 ppm, so a quarter gallon in 15,000 gallons is 10 times 0.25 times 10,000 divided by 15,000, about 1.7 ppm. The worst thing this customer can now do is 1.7 ppm, which the next visit absorbs, and that is the test the ceiling was set against.

The dilution ran the same week. Taking 95 ppm to a 50 ppm target means replacing 1 minus 50 divided by 95 of the water, which is 47 percent, and that holds only if the fill water tests zero for stabilizer, which the partial drain SOP requires be measured rather than assumed. Then the number that pays for the hour spent on the card: the drain buys back 45 ppm, and at the customer's own 3.9 ppm per week the tablet habit returns it in 45 divided by 3.9, about 12 weeks. Sell the dilution without the card and you have sold three months.

Step 8, next weekly visit. Free chlorine 4.6 ppm against a floor computed on the new 52 ppm cyanuric acid, which is 52 times 0.075, or 3.9 ppm. Above the floor, no unexplained movement, tier holds, verified off the work order rather than from memory.

References

• The product label on every container, which carries the legally binding directions for use; a card may restate a label figure and never override one.
• EPA registration of sanitizers and algaecides as pesticides, which is why use inconsistent with the labeling is a violation.
• Manufacturer safety data sheets for trichlor, cal hypo and muriatic acid, for the contamination cases at step 4.
• See related: Water Chemistry Out of Range Response; Cyanuric Acid Management Standard; Partial Drain and Dilution Decision; Chemical Storage and Transport on the Truck.