Re: [APD] Trace elements and algae

[Thomas Barr <tcbiii at yahoo_com>]

Bill wrote:

"Tom said, "I've heard this for years and to date I've never
been able to
induce any algae of any sort using trace elements."

Here's how you do it:  Into a well-planted, stable, fairly
heavily stocked
20 gallon aquarium, pour about 2 ounces of Flourish.  Wait a
day.  The water
will be a lovely shade of green.  Wait a few more days.  It will
disappear. Of course, there are many other variables involved.

Now coincidence isn't causation, but I just never get green
water.  I have
many other kinds of algae, of course, but never that.  The tank
in question
has been clear since that episode.

Bill"
===================
I say:

I never had GW either till I added NH4 at high light. I had many
combinations, and high light tanks as well as low light tanks.
I've been adding high levels of traces the entire time I've been
in this hobby. "More is better" was something I thought as well
when it came to ferts and never had reason to doubt that adding
high traces causes harm and made sure there was enough.

My plants looked better and I had less issues growuing them than
anyone else around. I looked at ADA's photo's, the plants
appeared to be in similar optimal health. 

Then took that relationship with NH4 and extended it to fish
waste, fresh soil, manures, Decreased growth(say after a few
weeks of high CO2(35ppm), drop it(say 5 ppm) for a couple of
days)and thus the balance of NH4 uptake that is being produced
from fish/plant waste, anything that causes a pulse of NH4 into
the water column or backup of NH4 assimilation from bacteria
into NO2/NO3 or plant biomass.

I've done this a number of times for each group of NH4 related
treatments. At lower light, many cannot produce GW. Other algae
tend to be induced but *slower*. We get more variation of the
timing and species induced as well as light drops. 
This makes since if you look at light as a contributing factor.

I'm actually surprised that there are not more multiple
interactions in our tanks and that some nutrients are magic
bullets for the most part. 

Light certainly can induce algae if the nutrients are limiting
for plants and CO2. So that needs to be considered. It affects
timing and growth rates ___a great deal__.  

To prove cause for GW and NH4 is very difficult, but the
relationship and hypothesis I've suggested is highly suggestive
of a cause in light of any other alternative hypothesis. Simply
because someone has not put forth an alternative hypothesis does
not mean one does not exist that may be better. But I think this
one I have now will be more evolved and entreched with time. The
bones for the causes appears to be fairly reasonable and able to
explain why the algae germinates, and it's a rather hard
hypothesis to falsify. 

I have on the other hand, been much more successful at
determining what something is NOT. Such falsification methods
are real myth killers. But you need to be sure what you are
testing for and seeing is really falsification or not and why
others might not see what you saw.

That's a much easier question to answer and rules out other
alternative hypothesis such as "Does excess Fe = algae?".

I've added 200mls of Flourish to a 20 gallon tank and let it sit
for a week.

No algae. No shrimp deaths, no fish issues.
The water was tea colored.
Note:this amount is 200mls/59mls higher than your suggestion,
333% higher and 7x longer with no ill effect noted.

Lighting is 450 umols, quite high.
It was a waste of Flourish really.

Adding much more 5-10mls to such a tank over a 2-3 day peroid is
a waste for that matter. Not sure why you'd add 59mls, but
still, you did and I added a lot for another reason, the person
taking care of the tank messed up when I took off for a week. 
I think if you are adding 10X the suggested amount based on EI,
you are getting out there a bit don't you?

For your tank:
My bet was slightly lower CO2 than optimal could induce the
greenwater, and adding Fe to a Fe limited tank will certainly
drive photosynthesis faster, limiting it thereafter would also
slow PS down. Thus CO2 uptake take was faster when you added it,
leading to low CO2 and slightly stunted plants=> downregulated
NH4 use(Cannot use it if there's no carbon frameworks to attach
it to) once the supply of CO2 drops too low for the plants to be
efficent at NH4/CO2 uptake.

Plants just do not go merrily along full blast unless there are
non limiting nutrients and stable conditions.
If you add Fe and get algae, you likely have a downstream effect
occuring.

I can see this and am confident, much more than you, that this
is what occurs in this tank. It explains why my tank does not
have algae when I repeat this test and why yours does after you
add it and why the algae goes away thereafter.

Do you have an alternative hypothesis that is more plausible?

This is a common downstream effect when a limiting nutrient is
added to the system.

And it's also a good example of why you have to be careful
ascribing cause to correlation.

When we added PO4, that drove PS(photosnythesis) faster and
folks assumed that high PO4 = algae.

But adding the PO4 with non limiting CO2 did not.
Several folks confirmed this and I'd been doing it all along
without ever measuring the CO2 or PO4.
But I did know then that PO4 was not the issue.

I did not know it was CO2 until.........I tested it:)
So testing is pretty important.....not for just diagnostics,
rather, to see what is really going on and to be sure you are
not being influenced by confounding factors.

Try bumping the CO2 up some and adding the Flourish again.
See if you can prove this to yourself(since it obviously
interest you).

I've seen this correlation monkey business start a dozen
myths(K+, Ca++, Mg++, NO3, about every nutrient there is, but
oddly few focused on CO2 other than my nagging self.....) and
I've chased them each down and beaten them to the ground.

when you remove such fears based on myths, then that frees us up
to focus on other issues and allows much easier management for
the tanks, eg, now no one bothers with fretting over PO4 levels
= algae etc unless they are too low ironically.
A decade ago, the opposite was true and I got into many tangles
with this.

It was not until folks actually came, tested the water, then
tried dosing PO4 themselves and saw the effect and had no algae
did anyone believe me.

But that was a simple falsification test and ruined the
hypothesis that "excess PO4 induces algae germination".
 
Regards, 
Tom Barr

www.BarrReport.com 




 
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