How dark after lights out

[lokii_37]

my tank stand is just a 2x4 frame so it is totally open on the sides. i have a sump with chaeto in it and i wanted to run the lights on the sump after the DT light go off to reduce the night time PH swing. Because the stand is open it does not get completly dark. So I was wondering if this is ok for the corals? In the not to distant future i will be making a new enclosed stand but for now I only have the frame.

Nick

[MaxxedMan]

We'll need someone who knows corals better to give you a real answer, but here is the one you should ignore.

It's its not direct light, i doubt it matters. I run my lights starting at noon so they get indirect sunlight 1/3 of the day. Never heard much about a little bit of reflected light being bad for corals.

[drparker]

Leave the sump light off for a few hours so the tank is dark, observe your corals and the polyp extension. Turn it on and check an hour later, if the corals look the same I'd say no big deal.

If however your corals have retracted the polyps then you have your answer as well.

[shaginwagon13]

My tank is never completely dark. At night time I have the moonlights on for night time viewing and I have done that since day one and never seen any problems. I also run the sump light at night (12 hours on and 12 hours off) for my chaeto. Your corals are fine IMO they are more rugged then most people give them credit for.