[blind_judge]

I'm a newbie in saltwater tanks but have been a hobbyist (fresh water). I was just wondering how long one should keep lights on? And should it be during the daytime or at night. Thanks in advance.

[patsfan1130]

Originally Posted by blind_judge

I'm a newbie in saltwater tanks but have been a hobbyist (fresh water). I was just wondering how long one should keep lights on? And should it be during the daytime or at night. Thanks in advance.

It depends on what type of tank your running. You can run your lights as little as you want if your running a F/O. I would say 5 hours or so if your running a FOWLR and 9-10 hours per day for a reef (obviously taking sunrise/sunset into account)

[showfish]

This question really depends on the animals you intend on keeping. However, IMO your lights should be on based on what they would normally be on in the natural environment. If you have live rock in your tank, you might want to keep them on at least 8 to 9 hours a day for the promotion of coralline algae. Regularity of photoperiod can be very meaningful. Experiments have shown that long dark or light periods (1-2 days) severely affect aquatic life, photosynthetic and otherwise.

[BubbaWPB]

Most people keep tropical animals in their tanks - reef or fish only. In the tropics (near the equator) day and night are pretty close to equal most of the year - so 12 hours on and 12 hours off is a pretty common practice.

[sihaya]

I think that to some degree it also depends on what light you have. It seems that many seasoned reefers do not keep metal halides on for 12hrs/day... I believe 10hrs/day of MH light is prefered (with 2hrs/day of lessor intense light... for example, one hour for dawn and one for twilight). But I'm not sure if there's any thing to this method. I know Sanjay Joshi is the premium lighting expert though. He has a lot of great articles on reef lighting.