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[APD] RE: Why algae don't grow and the plants do

> I'm going to pick apart a few comments so far, I'm challenging views to
> provoke discussion, not to be a jerk, so sorry if my comments seem a
> rough, it'll be good for all of us in the end... :)

Rougher the better, as long as they are about plants.

> Okay, so within the Barr framework,

?Barr framework? hehe. You peoples.

> what do I do about attached algae?  Do
> these melt away also?

I hack the little suckers off at their basal stalks. 
It's the new growth that bothers me.
Those are the ones I want to take out. You stop the the new growth, you
stop the algae. 

  What about BBA in the substrate/on driftwood (this is
> a huge problem among even the most seasoned growers)?

Not me. I can kick it's butt any day of the week.

>  Why can't we isolate
> this chemical, bottle it and make millions?  The market for a chemical
> this is enormous (almost all of it outside of the aquarium industry). 
> comments apply to Jim's reply, if these chemicals existed they would be
> commercially available already and this would not be an academic pursuit.

Yes, they have tried a few different things, but nothing works well.
I think this is good, since it forces folks to think about the plant's
health and needs to achieve the desired effect.

> Maybe.  Walstad method is based on the sequestering of nutrients in the
> substrate, allelopathy is a part of her story but the bulk of it involves
> getting nutrients to where the algae can't be: in the substrate as well as
> floating plants to take advantage of atmospheric CO2.  These chemicals
> not been isolated yet, I don't believe they play any role in our tanks...
> am not incorrect in saying evidence for allelopathy is shaky at best, Tom
> himself doesn't believe they play a role if I recall correctly.

See eariler post on allelopathy.

> Then please explain to me why hooking a bottle of O2 up to the tank,
> H2O2 to the water column, running an ozone machine, or any number of
> I can use to supersaturate the water with these chemicals fails? 

Well it depends. O2 did not reduce the over all algae levels if you use
Chlorophyll a, but the species did change.
Some algae have no problems with high O2 leevls, 200% satuaration? No
problem for things like Lyngba, see (Bowes some year but Lyngba is in the
title of the paper).

 Not one
> person has ever answered this question for me (with a reasonable
> explanation).

H2O2 is different than adding O2.
Same for O3.
All are intense oxidizers, with different effects. 

You can kill opff some species of algae with O2, but also your fish, same
with H2O2.
O3 is worse since if it's out in the water, it'll damage things worse than
the other two but all three can kill in high enough levels.

The best safe way: make the plants grow well so they produce the O2.
I think perhaps algae and other processes in our tanks are set up to "hear"
or listen to this diuranl cycle of O2 levels, going up inthe afternoon from
photosynthesis and declining at night when the plants stop producing O2.

We know it's not pH, our pH's are relative stable, you know it's not
allelopathic chemicals, Ole and I will argue you till you die on that one.
Simply add activated he tank to prove this(it'll remobve the allelopathic
Herbivores can be added and removed to note effects.
Fish waste can be added, deleted by feedings, reducing biomass of fish etc.
NH4 can be added(don't do this unless you know that you will get algae and
know what amounts that you are adding etc).

It's not so simple as we might hope.
That I do know.
I think that O2 levels play a large role.
I think NH4 competition plays a large role.
I us, you and I, going in and removing the old, half dead overgrown parts
of the plants, trimming off the algae manually, Large water changes(Removes
any residual break down from the organic nitrogen pool), stable food supply
for the plants, export of waste vuia pruning, filter cleaning etc, filters
converting NH4=>NO3, light controls, CO2 for some species all play a role.

The more of these things you do on a regular basis, the closer you are to
having a nice algae free tank. Some folks get lucky and hit right off. 
Many don't. 

I'll address non CO2 tanks in another post.

Tom Barr

> Good posts,
> Jeff Ludwig
> Elkton, MD

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