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Re: continous lighting or timed ?
> Jose Perez wrote:
> > Hi folks,
> > I am curious to what type of lighting setups people use here. Do you light
> > the tanks for 8 hours, 12 hours or do you leave the lights on 24 hours ?
> > Pros and Cons?
I use fluorescents that span the length of the tank.
I switch them on about 8h00 every morning and put them
off around 0h00 every night. There is fantastic algae
growth in the shallow notho tanks but I'm happy with
that... There is minimal algae growth in the Aphyosemion
tanks which have a varied assortment of plants.
On 19 Jul 2001, at 12:45, Wright Huntley wrote:
> I once accidentally sterilized a line of guppies by leaving the lights on
> 24/7. I don't do that any more.
Most animals and plants use day/night signals to reset
their body clocks. No signal, no resetting... hormonal
chaos... except with the Ghost crabs which can sit
months in the dark and still keep regulat day/night body
> Fish need their biorythms. The change of day length with season is an
> important breeding trigger for some, I think, too.
Quite correct. You can also fool plants in flowering by
manipulating day/night length as with fish. Most of the
triggers are multifactorial though and may have to be
paraleled with a rise in temp.
> Another argument against constant light is that vascular plants need a dark
> period of respiration (as opposed to photosynthesis) to grow. Simple algae
> do not, and can outcompete the plants for food unless there's a daily
Not really true... When my brother was too lazy to
switch his light of for a year we witnessed the most
fantastic amazon sword and eelgrass growth yet! The J.
moss and fern also went berserk. As said before though
the day/night cycles are NB in getting them to reproduce.
*Everyone not interested in plant biochemistry can now
The dark respiration you talk about refers to
photosynthetic reactions which can be carried out in the
dark---the socalled dark reactions. They can and are
carried out just as effectively in the day. During the
dark reactions the chemical potential energy generated
by harvesting light is used to convert CO2 and H+ into
carbohydrates with ATP and NADPH (an electron carrier).
The dark and light reactions occur simultaneously in
plants if adequate light is present. Interestingly, the
dark reactions require light for maximum rates of carbon
Needless to say, as a biochemist I've always enjoyed
plant physiology---plants don't scratch and scream when
you grind them up into little bits to find out how they
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I'm too lazy to use my spell checker.
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