Tom, most of what you wrote is well reasoned. Some points
I'd like to see expanded upon noted below...

wrote:

O2 levels decline as since the plant production rate is declining
also.

You might want to elaborate here. Yes, sick plants will
produce less O2. But, otherwise, most freshwater tanks are
at near saturation for O2. I won't say "all", but even
aggressive CO2 dosers who actively work to limit air/water
interface (a mistake IMHO) usually fall short of bringing O2
levels too far below saturation.

Are you working in the ranges of mild super-saturation?

Bacteria may also rob algae of any trace amounts of NH4 due to the
higher O2 levels from healthy growing plants.

This is the best idea thus far:

Algae spores may not have any signal like = NH4 presence telling them
to
grow(plants remove all the NH4 when they are healthy, bacterial
removal also occurs rapidly when the O2 levels are higher).
So very low/absent NH4 may tell algae that someone else is there.

Perhaps.

But you may have to navigate another issue here. Most
aquariums are 1) GROSSLY (orders of magnitude) over stocked
with well established bio-filter surface area; 2) exhibit
high flow rates through that bio-area; and 3) are near O2
saturation from their air/water interfaces.

High NH4 would seem a fairly extraordinary event. Inmate
death, sudden gross overfeeding, chemical induced death of
the bio-filter surfaces, etc. While algae seems a fairly
routine event, and is generally "present", if slowly
growing, in all tanks.

Another two stage pathway:
High O2 levels may activate bacteria in the substrate that suppress
algal
spores

Might spore/cells simply be sequestered in the bio-films? I
can enhance the spread of green spot by simply disturbing
the substrate. Liberated "bits" that land on various
surfaces, like (even healthy) plant leaves, seem to support
the sprouting of new algal spots.

that are generally present in the substrate much like a seed
bank/reservior.

I'm with you 100% here. Seed bank, POP, localized decay
(NH4), whatever, nothing good ever comes from particulates.

Shallow lakes are very prone to wind resuspension of nutrients from
the
sediments. This allows a bloom of algae since it suspends NH4(and
other
nutrients)
Macrophytes reduce wave action and prevent resuspension and this leads
to
gin clear water. There is some arguement with this theory but it seems
correct to me from what I've read about resuspension.

I'd like to see how you equate a shallow lake, with a few
feet of "muck" as substrate with a typical aquarium's few
inches of epoxy coated gravel. Or mine, with a couple of
inches of large river rock that stays 90% debris free and is
surely O2 saturated.

I can surely see how shallow lake processes can liberate
significant nutrient spikes, including NH4. I just need to
see the connection between the lake and why my aquarium
(with comparably no similar nutrient bank of a lake).

We do this when we replant and rework the tank, doing a water change
right
takes care of this.

Ok, let me explain my tank a bit. 2-3 inch water polished
"river rock" over egg crate. Much of the system's water
flow is from left to right, and remains under the egg crate
(underground river effect). On "intake" to the filter pump,
a valve splits the flow between the river and the overflow.
(creating an RUGF water flow through the rocks)

Obviously, I can trigger resuspension of debris tramped at
the rock-to-rock interfaces. But there are remarkably small
regions and remain highly oxygenated.

When I clean, I tap a percentage of the flow and "dust" the
debris, which due to differential flow, tend to be sucked
downwards into the "river". But - not all - and where those
stripped debris land, algae is likely to appear.

Yet I'm still left managing algae. If I mis-dose/over-dose
I can, and have, triggered outbreaks. I've never dosed NH4,
as that would be foolish.

Points I'd like to see more on, I guess.

- While I agree most gravels are a mess, it seems unlikely
that an undigested (NH4 source) nutrient sink exist in my tank.

- When particulate debris that are present are disturbed
(stripped of their bio-film prison?) they are aggressive
algal sources.

Everything I've done with NH4 tells me it's the problem in natural

I'll admit, as much as I'd like to test this POV, I just
don't the strength to dose NH4.

You can try this by adding more and more fish to a thriving healthy
tank.
Once you pass by the rate of NH4 uptake by those plants, you provide a
ripe

Or these truly massive bio-filters everyone seems to have?

Not that NH4 isn't a problem, for some. A friend has a, um,
swordtail collection packed into a 20G. Lives on a farm,
nitrate polluted well, grossly overstocked (like 20 full
grown 5-6" adults, lots of fry, a billion snails or so), he
grossly overfeeds, and is probably the first truly under
filtered tank I've ever seen. The silly thing also gets 1-3
hours day of direct sun.

A mess to view, to be sure (he can't bring himself to kill
anything). But, he shows continuous low levels of NH4. He
has trouble with green water, probably compounded by
bacterial bloom, and uses a diatom filter once a week. He
Does 50% changes a week. He maintains a stand of Anacharis
(in pots filled with garden dirt).

Has also has a few spots of green hair algae near his filter
(clear inoculation) - but it is completely non-expansive.

In this case, the tank must be limiting on P (he shows none
on my not-so-sensitive kit) or some other nutrient (besides
Fe - his well has to much).

Then if you apply this to a CO2 enriched low light tank, then you get
extremely low algae presence as well.If you keep adding more and more
fish to a planted tank, you will get algae and it's not due to NO3,
PO4, K+, it's due to NH4.

I'm not sure you can so easily make that association.

If you add more fish, you must feed them more. That will
surely produce more NH4 (for Carp, at least, the rule seems
to be, about 14% of the protein in their food will express
as NH4). It will also cause your bio-filter to quickly
accommodate the additional feed rate.

But, my can of Tetra shows "Min. Phosphorus 1.3%" as well.

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