[Prev][Next][Index]

Yet another Balance and lighting posting ;-)

> From: "Ted Fidder, AT&T - Bell Labs, Denver" <fidder at drmail_dr.att.com>
> Date: Thu, 12 Oct 1995 14:30:07 -0600
> 
> } From: "shaji (s.) bhaskar" <bhaskar at bnr_ca>
> }
> } balance is a term for which I have no good definition
> } [seeking better definition(s)]
> 
> 	I would very much like to see more discussion on this topic. It
> would
> seem based on existing evidence that I am suffering the dreaded "out of
> balance" problem on my 180gal show tank. Given I have optimum levels of
> measured CO2 (with a sandpoint controller), as much light as I can get
> with 40W 4' lights (8 of them over a 2' wide tank) the only thing that
> I have come up with is a problem with my micro-nutrients. 

Sort of started me wondering a bit if maybe we're implying that there is
a magic formula or ratio of conditions which is going to magically do
away with our algae problems (or at least minimize them). Perhaps this
needs a bit of re-think. I'm going to (try to) summarize what has already
been stated by the others in my own words.

There are several ways in which a tank goes from being "OK" to being
"out of balance" = having too much algae for our tastes.
- increase lighting intensity or duration
- increase concentration of macro-nutrients
- incorrect pH
- insufficient CO2 (light & nutrients plentiful)
- lack of maintenance removal of problem algaes
- gross lack of one or more micro-nutrients

IMHO, there is no precise ratio of the above factors which is going
to be markedly better than other ratios within some reasonable range.
The KEY is to provide *acceptable* conditions for the plants which just
allows them to GROW FASTER than the algae!! We can inhibit the growth
of algae by removing it and populating the tank with algae scavengers
like fish and snails.

Algaes are opportunistic: that means that an improvement in conditions
which would be perfectly acceptable to the plants in a steady state
can be exploited more quickly by algae than by the higher order plants.
This situation is particularly true with increased lighting intensity.
Plants need to expand their leaf surface area, roots and vascular 
systems in order to make the most of the new situation.

At the new steady state conditions, there would probably be a net
decrease in the concentration of macro-nutrients in solution; otherwise
algae could flourish as in transition. Possibly allelo-chemicals are 
also increased to inhibit algae. With lots of healthy rooted plants we
can expect that there would be a good influx of water (and nutrients
from decaying organics) into the substrate. I expect that laterite
and the other substrate additives like clay, humus, vermiculite, mud
and peat tend to collect and concentrate those nutrient ions at the
cation exchange sites where they are available for root hairs but not
for the algae.

Proposition: Substrate additives play a bigger role in plant tank 
stability in high light conditions.

Question: Anybody give us an idea of the flow rates induced by various
plants into their root systems?

Steve