Re: "Balance" or "Steady State"

> Subject:Balance and lighting 

> Yes, long-term trouble free growth implies balance, but balance 
> is considered to be some relationship between CO2, light and
> nutrients) does not imply long-term trouble-free growth (You cou
> have a tank full of algae instead, because the conditions for gr
> plants and algae are similar.)  Both the criteria I listed above
> to be true for "balance" and "long term trouble-free growth of p
> to mean the same thing.

As I explained, and as I think you know, there is more to balance 
than _just_ the inter-relationship of nutrients, lights and CO2.  
There is also the balance between plant density, stocking levels, 
feeding and water changes. Basic tap water chemistry also needs to 
be considered, as do species mix among both the palnts and the 
animals. While I like Charley's "Steady State", "Dynamic State" 
terms, I don't think that balance (or Charley has given his 
blessing to the term, "equilibrium"<g>) is a _bad_ notion.  
Balance is not necessarily as simplified as you want to pretend it 
to be.
> >> Do you have a more precise definition?
> >
> >Well, from my art rather than science background, I think of 
> >balancing a planted tank as I do balancing a mobile.  There are
> >many, many possible variations.  on any axis of the mobile, you
> >must achieve a state of balance.  This can be done by adding mo
> >weight to one end of your support piece, lightening the other e
> >or moving the balance point between the two.  
> I like Charley's objective definition of balance/steady state: a
> measurable factors stay within some narrow range.  In my mind, t
> factors include not only light, CO2 and nutrients, but also plan
> algae, fish, etc.  I really like the fact that this definition o
> balance does not have subjective notions of good or bad.  It als
> applies equally well to fish-only tanks, reefs tanks, etc.

I agree.  When I wrote the response you are quoting, I had not yet 
seen Charley's posts.  HOWEVER,  I still argue that whatever terms 
you use, the concept is the same.  I never said that light, CO2 
and nutrients were the ONLY things that needed to be "balanced" to 
achieve a certain goal in a tank. I also have never said anything 
to infer that there was any absolute "good" or "bad" level at 
which to maintain a tank.  I firmly believe, (and think I have 
stated before) that every aquarist has to decide for himself what 
his expectations are for any tank. I think the CONCEPT _does_ 
apply equally to any type of closed system, where you call it a 
"steady state" or a state of "balance".

> We can then begin to talk subjectively about "good" and "bad" ba
> A tank that is in balance with lots of algae is not desirable.  
> intervention is required, that's good, and so on.

I don't agree completely here.  Some people don't _mind_ a fair 
amount of algae, and they are entitled to that opinion.  If the 
the algae is not over-running other species the aquarist is 
attempting to maintain, algae is not necessarily a sign of 
imbalance or a sign that the tank is not "steady state".  I do a 
fair amount of collecting in the wild, and there is often a _lot_ 
of algae on very healthy, well grown wild plants.  I _will_ agree 
that _most_ people prefer to avoid algae as much as possible.
> >>  If so, how do we determine from a set of conditions
> >> (light, CO2, nutrients) whether we have balance or not?
> >
> >Let your eyes tell you!  If the fish and plants are healthy, an
> >growing well, and algae is at a manageable level on a _sustaina
> >basis_ (and I'll quantify this here by saying sustainable for a
> >least a year or more)  the tank is in balance.
> This is where you and I still seem to have differences.  Presenc
> algae to me does not imply that the tank is not balanced.  It co
> balanced, but in an aesthetically unappealing way.

No, again, you are not reading what I said.  I said, "and algae is 
at a manageable level".  Where did I say that the presence of 
algae implies that a tank is out of balance?  

I wouldn't even go so far as to say that it is always 
aesthetically unappealing.  Brush algae coating a piece of 
driftwood can be quite attractive in its own way.  It is only that 
the sight of it strikes terror in our plant-loving hearts that we 
hate it so!<g>

> >This is not a static balance, however, because it is a closed 
> >system.  One of the items to be balanced is the the work the 
> >aquarist is willing and able to put into the system.  That too,
> >will vary depending on the situation.
> I'd like to leave the "amount of work" out of the definition of
> balance, and instead put it in the subjective discussion of whet
> a balance is good or bad.

Sorry, I can't do that.  There is no way _not_ to factor human 
intervention into the maintenance of a closed system.  Fail to 
maintain your tank for long enough, and it will prove my point.
> >> How does "out of balance" as a function of light, CO2 and 
> >> nutrients translate to "problems"?
> >
> >The problems are as varied as the systems themselves.  Algae 
> >problems are often a result of an imbalance between light and 
> >macronutrients, but could also be caused by too much light and 
> >enough CO2.  Too much light without sufficient CO2 can cause 
> >serious pH swings, but this can become even worse in the presen
> >of plants that are particularly adept at splitting cabonates.  
> >little light on a tank planted with light hungry plants can cau
> >a failure to thrive.  Lack of a specific trace element can caus
> >deformed growth.  Plant eating fish in the tank can cause holes
> >the leaves.  Shall we go on?<g>
> In retrospect, my original question was poorly worded.  The prob
> have is that you seem to be assuming that all problems can be tr
> to some imbalance between CO2, light and nutrients.  This is not
> in my experience.  It's possible to have a good blend of light, 
> and nutrients and still have lots of algae. In that sense, "prob
> and "imbalance" are not the same thing.  This goes back to the "
> balance the same as good healthy plant growth?" issue.

The question I answered was, "How does "out of balance" as a 
function of light, CO2 and nutrients translate to "problems"?" In 
the question, there was no mention of the multitude of other 
possible problems in any give system.

The PROBLEM is you _deciding_ what I am assuming.<g>  Again, go 
back and read my posts _carefully_.  NOWHERE have I said that 
these are the _only_ factors involved in "balancing" a tank, or 
achieving a "steady state".  When speaking to another person on 
this list, I assume, perhaps wrongly, that the other person has 
reached the level of understanding this.  Please try to read 
_what_ I say, and _not_ read any more into it than that.  
Statements taken out of context almost never tell the whole story. 

I hate to say it, Shaji, but you're tilting at windmills.  We 
agree on more than you want to admit. ;-)



> Subject: deformed growth


> My E.Maior's last two leaves were deformed. At the time the seco
> last leaf was growing, I was away for a week. My CO2 generator s
> working and I've stop giving Tetra Crypto Dungen for a month. Do
> that mean Tetra Crypto actually work? I'm back and I've started 
> and giving the Crypto again. This latest leaf is still deform bu
> see what will happen to future leaves. Can lack of CO2 cause def
> growth. Other plants do not have the symptom.

Oh boy!  You're asking the wrong person here.<g> I think Paul 
Krombholz is the person to ask which nutrient dificiency causes 
what specific problem, but here goes.

It sounds to me that your plants were getting _something_ they 
needed from the Tetra product since the deformed leaves appeared 
after you stopped using it. (and I assume from your note that you 
didn't start using something else?) In my experience, lack of CO2 
slows overall growth, but I haven't seen it cause specific 

> Are you the same Karen that Cryptocoryne article appeared in Oct
> AFM? I became interested and will be looking for more Crypts. I 
> only one C.Siamensis var. Ewansii, I think. It now has two baby
> plants.

Yes, I am.  I'm glad if the article made you take a closer look at 
this interesting group of plants!  It's fun to have babies in the 
"family" isn't it?<g>

 Subject: Re: Balance and Lighting

> I think I can handle "equilibirium".  Precise (or scientific) 
> terminology merely elminates the subjective component.  I can 
> accept "equilibrium" to be a synonym for "steady state" because
> the deltas are largely un-measurable in either case.
> I believe that "equilibrium" merely (and only) implies a limitin
> factor exists in forcing a state shift.  There is no subjectivit
> in this (limiting factors are ALWAYS present in steady state
> systems).

Oh, good... I'm worn out from arguing with Shaji!<VBG>


 Subject: EQUILIBRIUM = Steady State


> I am changing some of the principles used in natural resource
> management to accomodate our aquatic systems.  As a result,
> my definition of "steady state" includes the following:
>   No (observable) state change over time, as a result of
>     (1) natural processes (species and cycles present)
>     (2) environmental input.
> Resource managers ONLY include (1).  They never do (2).  I
> am proposing that our definition needs (2) because the aquarist
> for all practical purposes, IS the environmental input (light,
> water movement, nutrients, CO2, etc.)
> > At least in my experience, even the best aquarium doesn't rema
> > "steady state" without planned intervention.  [snip]
> > While as a whole, I would consider my tank to be "steady state
> > that the amount of CO2, trace elements, fish food, water chang
> > etc. remains essentially the same on a day to day basis, and h
> > for several years.  At the same time, there is the constant 
> > "tweaking" to keep various species where _I_ decide they shoul
> > stay.  So from this perspective, the tank is almost continuall
> > a "dynamic state".
> You (the aquarist) are simulating foraging or vegetative browsin
> by selecting what plant species (and how much) to remove.  The
> end result is a system that does not change (observably).  This
> is also done in the real world:  livestock grazing (or deer 
> browsing) simulates fire, and both selectively remove vegetation
> We don't have large mammals or fire, but we can have the aquaris
> fish, crustaceans, diseases, snails, etc. do the same thing.
> Because all human intervention falls under part (2) of my
> definition (environmental input), your system would be in steady
> state according to this definition.  

OK, I can buy that to. But it's another point that we have to make 
_sure_ that novices understand.

> Perhaps another time I will have to explain in detail the
> counter-intuitive influences of "geologic time".  :-)

Please do!  As usual, I am enjoying your input tremendously.

Karen Randall
Aquatic Gardeners Assoc.
Boston, MA