Re: Tonics, Peats, and Buffers

["David A. Youngker" <nestor10@mindspring.com>]

From: "Christopher R Brightwell"
Sent: Saturday, June 10, 2000 10:49 AM


> ...Phosphate buffers shouldn't be stressful to the fish provided
> that the aquarium is not overdosed.  Yes, algae growth and
> conductivity are certainly considerations.  However, algae
> growth can be curbed by maintaining a balance of good light,
> carbon dioxide, and nutrients, as I'm sure you are aware.  The
> use of iron supplements, and even nitrogen supplements, can
> often force plants to utilize excess phosphate in the water.

This would most certainly be dependent upon the specific *goals* you have in
mind for the tank itself. Considerations for intensively aquascaping a tank
sometimes conflict with those whose intent is the husbandry of the fauna
within.

Even in a heavily-planted, "Dutch"-style tank, where the only fish
maintained are those meant to compliment the scene, you cannot simply
"force" the uptake of a specific nutrient merely by increasing the
proportions of the others. The effect is achieved only if the other elements
are present in quantities restrictive enough to have become growth-limiting
factors.

Nor does it become effective until enough light energy is absorbed to
justify the increased uptake. All the way around - not just the excess
element, but all of the others you've increased in order to bring the
proportions back into "balance".

Seems like a razor-fine strategy to me. If I have an excess of a single,
controllable addition (which would seem to be the case if I choose the
buffer), it doesn't make for an easy time to bring all other tank parameters
in line with the self-inflicted wound.

But hey, that's only one consideration. There's also a large proportion of
the membership here that believe in bare or next-to-bare tanks for breeding,
growout, etc. What will absorb the excess in this case?


> ...As far as conductivity, that is a less easily remedied problem.
> By starting the aquarium with RO or deionized water, you will
> have very low conductivity to begin (depending on efficiency of
> the unit).  The amount of phosphate in the buffer will increase
> TDS and conductivity, but as the phosphate is pulled out of
> solution by plants and turned into cellular material, this
> process will "reverse".

Again, this is a very fine line to toe. And don't forget the other elements
you've added in the attempt to balance out the nutritional soup.

Phosphorus is only about the eleventh-most abundant element on earth. It's
essential to tissue production, cellular activity, energy production, a key
binder in genetic material - the list is quite extensive. Given its
pervasive presence, it's not at all difficult to source within a tank. Nor
is its addition a necessity to the tank's environment - the fish are fed,
plants and animals die and life goes on in a tank, so phosphates are
released and absorbed.

Do I need it as a buffer? Not really. Using it entails more work - certainly
not a very effective conservation or reduction in energy. Are there
alternatives to it as a sub-neutral buffer? Certainly - and of course a
combination of water changes and humics pop readily to mind. Is it more
"natural" than its alternatives? Not at all - just check any collector's
location data.

Water goes sub-neutral just being *unbuffered* - the pH of "pure" water at
atmospheric equilibrium is 5.6. The volume involved in a natural body of
water, along with the presence of humics, pretty much keeps it there. In our
closed ecosystem called the aquarium, the extreme level of relative
biological activity is what drags down the pH. The Amazon removes
accumulated wastes through dilution, we use a water change. But we can also
combat it with plants. Essentially, though, it takes an active effort on our
part to remove these wastes in some manner. Since these wastes are also the
source of our acidity problem, we are simultaneously handling that headache.

If water changes are an established part of your regimen, then pH control is
also. Why add something that has to be a pain to remove, especially if you
know you're just going to turn right around and remove it. And since it *is*
the buffer, how do you justify the extra expenditure of just throwing it
away? Excess discretionary income?

Want something a little higher than 5.6? Add a little bicarb. Nature's
primary pH control between 5.6 and 8.2 consists primarily of varying the
ratios of CO2 to HCO3-. Since the CO2 is held at atmospheric equilibrium, it
just becomes an easy matter of figuring out how much bicarb to add to pure,
aerated water.

This fact hasn't been missed by most of the major players in the commercial
buffer field. Those more in tune with the desires and practices of the
aquarium aficionado have moved to severely restrict or remove altogether the
phosphate content of their product lines, opting instead for mixes of
bicarbs and carbonates (pH dependent).

And most hobbyists are slowly learning that you can't simply add a powder to
hard, basic water and get the Rio Negro.

Now if we could only get them to use a blend of *different* bicarbs so as to
restrict the sodium input a little...

-Y-

David A. Youngker
nestor10@mindspring.com




-------------------------------------------------------------------------
This is the apistogramma mailing list, apisto@listbox.com.
For instructions on how to subscribe or unsubscribe or get help,
email apisto-request@listbox.com.
Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!