[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: light intensity
Steve writes:
> Is 250W too much
> light for a 60g tank thats 24" deep? Hard to tell. Its not as high a
factor as the
> smaller tanks, but still nearly twice what the 50g tank has at 2
watts/gallon. (the
> reason I ask is that I'm currently setting up a tank like that, and after
hearing the
> discussions here, I think I have too much light)
It's not nearly as much as sunlight , and if you took a photographer's light
meter into the woods and checked in the shade of the trees, you're still not
as bright as that at the bottom of the tank.
> I'm not sure that aquarium lighting falls off with the square of the
> distance,
> because there is quite a bit of internal reflection of the lights off
> the sides of
> the aquarium. It may be something like depth^1.5, but I really don't
> know.
A lot of light is absorbed by the water itself. Perhaps not enough to be
noticed, but it gets bluer fairly quickly. I haven't really considered that
before, but maybe a lot of extra blue would be better in tanks over 18". Or
maybe more red in order to compensate for the loss at the red end? I don't
know. But even when you aren't talking about light through water, the square
of the distance thing still applies. Even with spot lights.
Bob Dixon
Cichlid Trader List Administrator
http://cichlidtrader.listbot.com