heaters, heaters can keep it warm at night.

sunlight is shifted towards blue end under ocean water, not in a tank. we
need to mimic the color light that reaches the ocean reef, not the color of
th sunlight itself.

wolfhedd

"Rob Marston" wrote in message
...
Why is natural sunlight not used for fish tanks? To my knowledge metal
halides are the closest match to the real thing, but not as good. Using
natural sunlight makes a lot of sense, but whenever I ask the LFS, I get
answers like 'algae problems' etc.

In my experience the algae really does take off under natural sun light,
but
if you keep it starved of phosphates and nitrates then it does not seem to
run out of control. I found the key seems to be keeping a low bio-load
etc... Rowaphos and a good skimmer helped alot also...

As for any heating effects caused by the sun I found that evapouration was
more than able to compensate, it also allowed me to add more calcium in
the
form of Kalk. The only downside being that it makes the room very humid
and
an external extraction fan is recommended.

For me the main problem with keeping my tank in the conservatory was the
room temperature dropping at night. This upset my mangroves and they
needed
to be separately protected... However they seem to love the natural
light...

Rob