How much is too much light?

[spittinfly]

I guess I have to be specific and stop hiding my q's in a giant paragraph.

Right now my fish get about 15 hrs of light. Is that way too much and what is the problem if it is? Just too much algea or aggressive behavior?

 

[Jchillin]

That is a pretty long time. 10-12 hours is a bit better and you are correct, lenghty photoperiods do contribute to algae.

 

[Zagz]

I'd have to agree with Bill. I usually keep my fish in light for about 12 or so hours.

 

[ezy33]

For a FW tank without live plants, the only time you really need to light the tank is to see your fish. Unless the room gets no light at all. I light my FW for about a hour in the morning before I go to work, I feed them then. In the evening from 5 to about 10 so I can enjoy them. As many tropical come from jungle rivers that only get mid day sun and/or the water is dark or murky.

 

[Sidi]

For a FW tank without live plants, the only time you really need to light the tank is to see your fish. Unless the room gets no light at all. I light my FW for about a hour in the morning before I go to work, I feed them then. In the evening from 5 to about 10 so I can enjoy them. As many tropical come from jungle rivers that only get mid day sun and/or the water is dark or murky.

Even with plants 15h is probably too long. In my planted tank I was able to seriously reduce algae growth, without hurting the plants, by going from 13 h to 9 h of lighting. The light is timed so that it's on until just a little bit before I typically go to bed, so I can still enjoy the fish, but having 2.5 w/g for 13 hours was a huge algae problem.

 

[smn723]

Agree with JChillin and Zagz...10-12 hours is typical. Some may even go to shorter photoperiods (my friend does 8 hour photoperiod...just helps him keep things in check) when they have high light causing large algae blooms in longer photoperiods.

 

[spittinfly]

Well I will try to cut back my light time, but the fish are so darn cool I want to look at them all the time!