How Many Hours of Light Should an Aquarium Have?

How long you leave the aquarium lights on will depend on the type of aquarium you have.

Wide Ranges Can Work

For aquariums with only fish and no live plants or corals, the aquarium lights can be left on for anywhere between six and 12 hours per day. Fewer hours will discourage algae growth in the tank and allow your fish plenty of time to rest undisturbed.

Photo-period Depends on Your Tank

Coral reef and live-planted tanks may need significantly more than the six-hour minimum suitable for a fish-only tank. Some corals need up to 14 hours of light.

Bottom Line

Since long periods of intense lighting can lead to algae growth, start your aquarium off with a shorter day period and slowly work up in hours to accommodate your plants or corals, and your desired viewing time each day.

References

• FishLore.com: Aquarium Light
• Aquarium-Lighting-Guide.com: Lights