Re: Watts per gallon

> Date: Tue, 18 Jul 95 14:56:34 PDT
> >From: "shaji (s.) bhaskar" <bhaskar at bnr_ca>
> > [snip] 3 watts per
> >gallon of lighting, and CO2 with the yeast method are what I'd
> >recommend for someone just starting out.
> Actually, I noticed that the watt-per-gallon light requirement is not linear.
> >From Amano's Nature Aquarium World, I saw he used fewer watts per gallon for
> larger aquaria.  I don't have the book right here, but I remember that for
> large aquaria, it dropped down to under 2 W/gallon.

It really depends a lot upon the depth of your tank as well. Beginners
should be aware that these wattage requirements are really minimal
and will not be sufficient for some of the more difficult species such
as Cabomba. When the other conditions are right, CO2, sufficient nutrients,
a good substrate additive (such as laterite, vermiculite, or even well
decomposed humus), the results of strong lighting will be spectacular
growth. In my 75 gallon tank, 2'x 2'x 28" deep I use a 250 watt MH lamp.
This strong light is needed to penetrate this deep tank. All of the
plants are now showing excellent growth rates with minimal algae problems
on new leaves. I've just added 8 ottocinclus and 1 farowella to combat
green hair algae which exists on the older leaves of the Aponogeton
madagascariensis. The A. mad. is recovering from the transplanting and
I suspect, reestablishing it's extensive root system. It would appear that
it is important to trim off the older leaves from this plant regularly
to encourage new growth. A good substrate to support the roots is
critical IMHO for this species. So far, I am getting good results from
the mixture of gravel, vermiculite and earth worm castings (humus).
It is perhaps a bit more compact than I'd like so I'd recommend the
reduction of humus to about 7% in the middle 1/3 layer. The top 1/3
and bottom third are straight gravel; the middle is 15% vermiculite,
15% humus. Do not use any of the commercial potting soil mixtures
where peat or particles of small brown organic fibers can be seen with
the naked eye. This is undecomposed organic material and can lead to
unwanted anaerobic decay in a substrate. UG heating cables are advisable
with clay, vermiculite or humus containing substrates. I'm experimenting
with a super slow reverse UG flow system. (see previous posts)
Some may (correctly) argue that you can achieve good results with
much lower lighting intensities. It is really the proper combination
of all conditions which permits the use of such strong lighting.
150 watt MH lamps are much more commonly used with the typical 18"
tanks. Why should reef people be the only ones to enjoy the benefits
of MH lighting?

 - Steve