Depends on the fish, and where they are from. Water from the amazon is quite clear in areas, and gets high sunlight, and in other parts, it can be very murky, with low levels of sun.Scottfree;1457978;1457978 said:I believe daylight is 6500k, but I personally prefer lower lit tanks. I have no scientific proof but I think it's better for fish to be in lower light, in the wild they get very little direct sunlight, and would usually be in murky algal filled waters which would shade the light.... 2 cents