Balance and Lighting

To: Aquatic-Plants at actwin_com
Subject: Balance and Lighting
From: krandall at world_std.com (Karen A Randall)
Date: Sat, 14 Oct 1995 19:04:43 -0400
Re: Balance and Lighting


> It is true that "balance" has no wide-spread biological 
> definition.  If I was forced to define it, I would probably 
> state, "Balance is that point when all factors in the system 
> become the limiting factor simultaneously."  Of course, this 
> is a somewhat arbitrary definition based on preference.  That's
> my definition because I'm a tight-wad and I don't like the idea
> of wasting too much of any one factor.  For me, the system isn'
> in balance if I'm wasting too much of any one thing.  

That works for me.<g>

> An equally
> valid definition would be, "Balance is that point when system 
> deltas (system changes) are minimized or severely restricted, as
> the result of at least one limiting factor other than time".  
> This is a little more esoteric, but probably more appropriate 
> to the universal scientific audience.

Trouble here is that most keepers of planted tanks are _not_ 
scientists.  They are enthusiastic amateurs like me, trying to 
make sense of the bits and pieces they pick up as they go.  
 
> The REAL problem here is, "What do we want to balance?"  This
> is *not* something we can universally define.  We must go throug
> the exact same process that one would go through to determine
> the *personal* economic "opportunity cost" of any action or 
> inaction, which (of course) is different for each individual.
> "Do I balance plant growth with the highest possible fish
> population?"  That *might* be measurable.  How about "Do I
> balance these two plant species, (with different light and spac
> requirements) and what is most visually pleasing to me,
> against the highest possible fish load?"  Forget it.  It can't 
> happen.  You will never quantify that in any reasonable manner.

I think that's very close to what I was trying to say.

> Most biologic resource managers don't ever address the concept
> of "balance", but prefer to refer to the dynamics of a system wi
> a concept of "state-shifting", or "steady state".  The reason 
> for this is simple:  When we are not (readily) capable of 
> measuring the end result, we must revert to measuring the 
> deltas (the changes) that we are able to observe in the system.
> When there are no deltas (no "state shifts"), then we must have
> achieved the end result (a "steady state").  Take-home message:
> DELTAS ARE SCIENTIFICALLY MEASURABLE.

See, you scientist-types _can_ come in handy.  I like that.  I 
think this is what I've been trying to say all along, without 
knowing the exact words to say it.
 
> This concept of "state-shifting" is not purely academic;  it
> is tremendously practical.  Because my ears have grown sensitiv
> to the accurate selection of precise terminology, I would prefe
> to hear people mention they have, "...reached a steady-state 
> that is particularly desirable, GIVEN THE SYSTEM INPUT 
> PARAMETERS" as opposed to state they have "reached balance".  
> That's just me, though--I can get by with any terminology,
> usually.  :-)

Now the problem is to get the terms into common usage.  I started 
using the term "balance" for lack of a better term.  What ever we 
call it, IMO it is this CONCEPT that is so important.  And doesn't 
change no matter how "high tech" or "low tech" the tank.
 
> > Is balance to you a yes/no proposition (i.e., either there is 
> > or there isn't)?  If so, how do we determine from a set of con
> > (light, CO2, nutrients) whether we have balance or not?
> 
> Personal preference.  :-)  How much work do you have to do to
> get what you have?  I can make a good argument for the following
>
>   if( work_and_inputs_required < benefits_achieved )
>     /* We think we have balance. */
>   else
>     /* We don't think we have balance. */

Again, I agree.
 
Thank you once more for a very enlightening and thought provoking 
view point!


Karen Randall
Aquatic Gardeners Assoc.
Boston, MA