Seafood stall equipment technician - the monthly aeration maintenance checklist: air stones, airlines, pump diaphragms, backup pump rotation, catching decay before it detonates

Write me a monthly aeration maintenance checklist for a seafood
stall, laminated and posted at the pump station, ticked item by
item on maintenance day. It covers air pumps, airline runs, air
stones, check valves, and the backup pump. Structure: one row
per item, three columns - what to check / what counts as wrong /
what to do right now. Every judgment is a comparison: against
the same pump and the same tank at the last maintenance, never
against another stall and never against an imagined standard
value.

Item zero (safety, always the first row):
- Kill power and unplug before any disassembly. A seafood stall
  has wet floors and wet hands; working a live pump is the only
  step on this list that can kill a person - if this row is not
  satisfied, nothing below it happens

One, every maintenance day:
- Air stones, one by one: for tanks whose surface agitation
  dropped a notch versus last month under the same pump, pull
  the stone and check for clogging. Scrub it clean; if it won't
  come clean, replace it without hesitation - an air stone is
  the cheapest part in the system, and betting on one is a bad
  trade
- Pump intake filter foam: remove and check for dust loading.
  A clogged intake is suspect number one for falling output and
  the cheapest fix on the list: rinse, refit, replace if it has
  gone stiff
- Airline runs: walk the line and listen for hissing at each
  fitting; replace any perished, whitened section as a whole
  run, never splice a patch into it - every fitting you add is
  a new leak
- Check valves: the moment a pump stops, watch the airline for
  water siphoning back. Any backflow means the check valve is
  dead - replace it, or the next outage pulls tank water into
  the pump body
- Power plugs: kill power, then put a hand on every plug. Any
  that runs hot, has blackened or corroded contacts gets
  replaced whole - no sanding it into service. In a wet, salt
  air environment, plugs are the invisible failure point

Two, on schedule (intervals come from each pump's manual, the
checklist leaves 【】blanks - it does not invent numbers for
the manufacturer):
- Pump teardown (diaphragm / piston / impeller, by pump type):
  a pitch rising in the sound, a body running hot to the touch,
  a rhythmic knock → the interval has arrived, tear it down
  before it stops for good
- Backup pump rotation: test-run it monthly and log
  "normal / abnormal"; rotate it into duty with the main pump
  where possible - a backup pump also dies from sitting
  (rubber parts perish at rest), and a backup that has never
  been run is a fake backup

Three, records:
- One page per pump: date / what was done / what parts were
  swapped / what is due next. "When did we last clean the
  stones" must be answered from paper, never from anybody's
  memory

Constraints:
- Every item must be a physical action. "Inspect equipment
  regularly" and phrases like it are banned - one empty item
  and the whole checklist forfeits its credibility
- No invented service intervals: copy them from the manual into
  【】, and where the manual is silent, ask the manufacturer -
  the checklist does not fill the manufacturer's silence
- This list owns "maintain and catch early", not "repair" -
  breakdowns go to the repair-call workflow; blend the two and
  both suffer
- Judgments state the comparison only (weaker / silent /
  running hot); no "how much longer will it last" predictions

Format: single A4 page, three-column table; the per-pump log
pages attach behind it.

Why it is written this way

Aeration failures are almost never sudden. Stones clog over months, diaphragms fatigue over weeks, and the decay is painless the whole way - until the first high-density summer day, when a system already running at thirty percent gets loaded to full and half a tank dies. The stall remembers "it failed out of nowhere"; the checklist's entire job is to intercept that story during the quiet part, which is why every item targets a specific decay mechanism instead of a generic "check the aeration."

Every judgment is "against itself last month" because absolute values do not exist in this trade: tank depth, water volume, pump model, airline length - no two stalls match, so there is no universal answer to "how strong should the bubbling be." But "this tank dropped a notch since last month" is legible to anyone. The comparison standard also removes the skill barrier - nobody needs to know flow parameters, they only need to recognize change.

The safety item sits at row zero with the rule that skipping it means the checklist never started. On real maintenance lists, the safety row is the first thing people skip precisely because it produces no maintenance result. Making it the gate - nothing happens unless this row closes - turns a poster slogan into a physical order of operations.

"Replace the stone, replace the run, replace the plug" are deliberately anti-thrifty instructions. Stones, airline, and plugs are small money; the time spent judging whether they "still have life in them," and the cost of judging wrong (one die-off event), dwarf the parts bill. A maintenance checklist does not teach repair - it teaches which things are not worth repairing.

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