Light Pollution

[himegs]

I've been wanting to set up a show fuge next to one of my reef tanks, but I can't come up with a way to keep the fuge lighting from affecting the reef tank. (Without looking really ugly, anyway.)

But that started me wondering how much effect the other house lights have on my corals at night. I have one tank that is relatively near a hallway light that my daughter likes to leave on at night. We also leave a kitchen light on most nights. And even though it is not very bright in the next room where the other tanks are, it is still far from night-time darkness. Some mornings I notice that some of my tank inhabitants don't seem to have closed up at all overnight.

So the questions are these: just how detrimental is background house lighting to a reef tank at night? Is it necessary, or better, to have a period of total or near-total darkness?

[NateDogg]

My tank is in an area where there are lights on for a large portion of the evening and early morning. I haven't been in this hobby for very long at all, so I don't know what affect it has had on the corals. I have observed differences in my fish. They seem more active when they get a good nights sleep. It may be a coincidence, but I do think there is an affect. I am interested to here every one elses opinion.

[JimD]

Cool topic... I would think that the fish and corals benefit from total darkness occasionally.

[Texreefer]

I would say almost no effect at all, shallow reefs are almost never completely dark. my fuge light casts enough light that I can see almost everything in my tank any time. we also leave a light on in the hall for our son and I have seen no Ill effects

[Mr Cob]

I would also say that it's probably not a big deal because it's the same as a full moon in a shallow reef. As long as you have caves the fish can surely escape the light if need be.

[vman181]

I would also say that it's probably not a big deal because it's the same as a full moon in a shallow reef. As long as you have caves the fish can surely escape the light if need be.

I would have said the same thing as Mr. Cob. With a full moon or even a half moon, there will be light in a shallow reef.