Define requirements and constraints
Record the baseline and check plant or coral demand and water depth. Do not infer the aquarium's condition from a single sign. Measure the real space, identify connections and preserve clearance for cooling and service.
Then compare photoperiod, intensity and ambient light with livestock needs and recent changes. Compare useful capacity, energy and compatibility with the complete setup.
Install for future maintenance
Adjust one variable and assess a stable schedule that exposes growth and algae response before continuing. Keep a reference so the result can be compared. Test the assembly under controlled conditions and record settings that must be repeated.
Do not choose lights by watts alone or raise intensity and duration together.