Measure and add context
Record the baseline and check peak temperature and the daily trend. Do not infer the aquarium's condition from a single sign. Record method, time, temperature and recent changes so the reading can be compared.
Then compare ventilation, evaporation and equipment capacity with livestock needs and recent changes. Assess the trend alongside breathing, behaviour and species requirements.
Correct without destabilising
Adjust one variable and assess a gradual reduction supported by aeration before continuing. Keep a reference so the result can be compared. Address exposure or cause first, then retest before stacking products or interventions.
Do not add large ice blocks directly; they create abrupt local changes and alter volume.