Now, Bio 1, not even 101, teaches... "A Species will
proliferate unless, or until, it encounters a limiting
factor". A proper biological argument, surely any regarding
population control, is framed in terms of what "limits" that
species, and that species directly.

But that is in an _ideal_ situation in order to show the concept, not
to be applied without consideration of many other variables.

There are few macrophyte periphyton competition studies.
This is not Bio 101.

I gave several mechanisms that do in fact limit growth in an aquarium
algae.
Not just one. It also works in non CO2 plants tanks and marine planted
tanks to some extent.

This issue has been discussed several years ago on the APD in depth
and still here and there but no one contends that excess PO4 causes
algae. Paul Sears was part of that discussion, one of the authors of
the paer that you have referenced to.

There are also many exmaples of folks telling how well their plants
grow by adding PO4.

You have not supported your contentions, I have.
The proof is in the pudding, why don't I have algae like you seem to
want to claim?

Magic water?
Crystal powers?

When you do otherwise,
you open wider and wider ranges of potential causality.

Actually I have proven quite definitively that excess PO4 that is
available for both plants and algae equally, not not cause algal
blooms in planted tanks with good plant biomass, CO2, moderate-high
light, good dosing of the other nutrients.

If you want to talk about causual mechanisms, you need to be able to
isolate the issues and deal with PO4 in a controlled manner.
In order to say x causes y, you need to make certain that the other
parameters are not influencing your results.

Steve Dixon and I were some of the first people to do this in planted
tank context regarding PO4. I also showed that NH4, not PO4 or NO3
caused Green water and staghorn algae blooms in FW planted tanks.

Algae/BGA exists. If, as you claim, higher plants are
limiting, they are doing it through bio-chemistry.

Higher plants are limiting the algae?
I do not think they do it through alleopathy, you can add activated
carbon to the filter to remove any organic compounds that cause
allelopathy.

Also, look up the APD and other sites.

Name the
link.

?

We know it is resolvable, routinely, in various
media, without nutrient starvation of the higher organisms.

Some higher organism have different niches than smaller ones.

Resolution/limitation (in tank) rarely depends on
predation,

True but it can tip the scales in a few cases, it's not something I
rely on.

need not depend on antibiotic toxicity, and can
be accomplished regardless of lighting levels.

Regardless of lighting levels? You sure you want to say that?

Whine all
you want about PO4 "ain't it", Fe "ain't it", XYZ "ain't
it", but until you form a proper biological argument,

Oh, I most certainly have spelled it out quite well and better than
those before me.

spelling out what factors ARE "it", I'll go with the
nutrient limitation, thank you.

Uhm, I did in the last post, I gave multiple plausible causes.
You can believe want you want, you are still wrong.
Research shows this, I can show this in a plant tank, you can show
this to yourself in a planted tank.
The AGA contest winners, all the plant clubs have got it all wrong and
you are the only that's right?

Humm you might want to actually try it and see about this, maybe read
some of the references, ask around.

Hey, you can believe what you want to believe, but your still wrong
about PO4.
That does not change.
You have not supported your own arguements with a single reference
beside Paul and Kevin's.

Lighting is surely limiting, less light less stuff,

Depends, if light is limiting, then yes, but this is not always the
case.
Aquatic Plants generally are better competitors than algae for light.
Call up Dr. Bowes, the guy's studied aquatic plants and algae for 30+
years.
Ask.

but silk
plant tanks still do end up infected so "low light" is
hardly the complete answer.

I never said it was "complete".

You want a complete answer in aquatic plant-algae dynamics here?:-)

Temp is limiting, range
depending on species, but does the range 68-80 matter to
"our" species?

Not too much.

Redox seems implicated, but a well lit,
reasonably clean, plant tank tends to maintain a serviceable
redox on it's own, and I've had BGA at high redox in my reefs.

I did not say redox, but you could argue high O2 levels cause many
species of algae, BGA etc to photorespire causing large losses, up to
40-50% of the fixed carbon.

Reef tanks and plant marine tanks are different. Careful not to
compare apples and oranges, same thing goes for Northern deep minimal
littoral zone lakes used to make assumptions about planted tanks vs a
shallow warm water tropical lake packed full of aquatic macrophytes.

One is much more applicable to the questions at hand with planted
tanks.

Regardless, we all control light, temp, and less so redox as
a matter of routine. BGA/Algae comes and goes.

Mine does not come and go.
I have not had it become an issue in a decade or more.

It must be
resolving because 1) something in the water is killing it;

Well, carbon will remove organic causes, water changes also will
reduce the effects, it cannot be nutrients since we have added the
nutrients the BGa needs to live to excess.

or 2) it is failing to find something else it needs (nutrients).

Maybe it knows something else is growing, much like a seed that will
not germinate due to other plants surrounding it or until a fire comes
along and disturbs it.

Before you reply back, I'd suggest you look up and ask around about
this issue that we limit algae through PO4 or Fe limitation.

The observations all over the world and the winners in many contest
directly conflict with what you are saying, not to mention past
research.

Regards,
Tom Barr

One last thing:
I too wondered what the hell was going on when I noticed I had very
high PO4 levels but no algae, great plant growth.

It seemed blasphemy at the time as well. But the observation was
confirmed by many folks and has been for many years now.

So I did feel as you did at one point. It did not make sense at first.

Take care,
Regards,
Tom Barr

One last thing:
I too wondered what the hell was going on when I noticed I had very
high PO4 levels but no algae, great plant growth.

It seemed blasphemy at the time as well. But the observation was
confirmed by many folks and has been for many years now.

So I did feel as you did at one point. It did not make sense at first.

Take care,
Regards,
Tom Barr

wrote:
Now, Bio 1, not even 101, teaches... "A Species will

But that is in an _ideal_ situation in order to show the concept, not
to be applied without consideration of many other variables.

Nope, actually, "consistently applied" would be the thing.
Now, human processes are always subject to error,
miscalculation, observational limits, and oversights. For
example, one might miss "fish" as a mid-point between
plankton and seal control - but one would never, willingly,
ignore "fish" simply to dispatch with well formed process in
"consideration of many other variables".

and still here and there but no one contends that excess PO4 causes
algae.

Oddly, you still dwell on PO4 as a sole and distinct "cause".

There are also many exmaples of folks telling how well their plants
grow by adding PO4.

Hey, plants like PO4.


You have not supported your contentions, I have.

Eh?

The proof is in the pudding, why don't I have algae like you seem to
want to claim?

Magic water?
Crystal powers?

No, but I'd surly have difficulty with the notion of macro
sensibility through the "observational" powers of BGA
regarding relative health of local higher plants.

Actually I have proven quite definitively that excess PO4 that is
available for both plants and algae equally, not not cause algal
blooms in planted tanks with good plant biomass, CO2, moderate-high
light, good dosing of the other nutrients.

Anecdotal. If I can limit via P (in the world where 0 means
0), or I can limit via Fe (also in world where 0 means 0),
or I can limit via "Factor X", then...

If I choose P, and you choose "Factor X" (knowingly, or
not), then by your science, you can "prove" P is "wrong" all
day long.


If you want to talk about causual mechanisms, you need to be able to
isolate the issues and deal with PO4 in a controlled manner.

No, you have to deal with BGA in a controlled manner. PO4,
in science-pure water, won't support any form of life, at
all. You simply cannot control for P, alone, in the life
cycle of BGA.

Steve Dixon and I were some of the first people to do this in planted
tank context regarding PO4. I also showed that NH4, not PO4 or NO3
caused Green water and staghorn algae blooms in FW planted tanks.

Regardless of lighting levels? You sure you want to say that?

Absolutely. I've never, ever, reduced lighting on the reef
tank. BGAs are periodic, and routinely resolvable.
Anecdotally linked to DI breakthrough (and not Zeolite
breakthrough) in the input waters. Persistent NH4 is not
very likely anyway, considering the massive bio-area, water
movement, age of that rock, and unchanged populations of the
tank.

Plant tank is VHO, high PAR, low P. Same size tanks, same
wattage, both reef and plant.

Uhm, I did in the last post, I gave multiple plausible causes.

I reread, closely. Mostly "ain't it". Maybe I missed your
causes for your style.

You can believe want you want, you are still wrong.
Research shows this, I can show this in a plant tank, you can show
this to yourself in a planted tank.

Anecdotal, and the lake study is ill controlled.

The AGA contest winners, all the plant clubs have got it all wrong and
you are the only that's right?

Anecdotal.

Humm you might want to actually try it and see about this, maybe read
some of the references, ask around.

I live it. I limit P, provide high-light, dose PMDD, and
have very few problems with BGA/Algae. My plants out pace my
eagerness to prune, I surely care not to "improve" their
status any further.

Hey, you can believe what you want to believe, but your still wrong
about PO4.

Ain't it! Fine.

wrote:
Now, Bio 1, not even 101, teaches... "A Species will

But that is in an _ideal_ situation in order to show the concept, not
to be applied without consideration of many other variables.

Nope, actually, "consistently applied" would be the thing.
Now, human processes are always subject to error,
miscalculation, observational limits, and oversights. For
example, one might miss "fish" as a mid-point between
plankton and seal control - but one would never, willingly,
ignore "fish" simply to dispatch with well formed process in
"consideration of many other variables".

and still here and there but no one contends that excess PO4 causes
algae.

Oddly, you still dwell on PO4 as a sole and distinct "cause".

There are also many exmaples of folks telling how well their plants
grow by adding PO4.

Hey, plants like PO4.


You have not supported your contentions, I have.

Eh?

The proof is in the pudding, why don't I have algae like you seem to
want to claim?

Magic water?
Crystal powers?

No, but I'd surly have difficulty with the notion of macro
sensibility through the "observational" powers of BGA
regarding relative health of local higher plants.

Actually I have proven quite definitively that excess PO4 that is
available for both plants and algae equally, not not cause algal
blooms in planted tanks with good plant biomass, CO2, moderate-high
light, good dosing of the other nutrients.

Anecdotal. If I can limit via P (in the world where 0 means
0), or I can limit via Fe (also in world where 0 means 0),
or I can limit via "Factor X", then...

If I choose P, and you choose "Factor X" (knowingly, or
not), then by your science, you can "prove" P is "wrong" all
day long.


If you want to talk about causual mechanisms, you need to be able to
isolate the issues and deal with PO4 in a controlled manner.

No, you have to deal with BGA in a controlled manner. PO4,
in science-pure water, won't support any form of life, at
all. You simply cannot control for P, alone, in the life
cycle of BGA.

Steve Dixon and I were some of the first people to do this in planted
tank context regarding PO4. I also showed that NH4, not PO4 or NO3
caused Green water and staghorn algae blooms in FW planted tanks.

Regardless of lighting levels? You sure you want to say that?

Absolutely. I've never, ever, reduced lighting on the reef
tank. BGAs are periodic, and routinely resolvable.
Anecdotally linked to DI breakthrough (and not Zeolite
breakthrough) in the input waters. Persistent NH4 is not
very likely anyway, considering the massive bio-area, water
movement, age of that rock, and unchanged populations of the
tank.

Plant tank is VHO, high PAR, low P. Same size tanks, same
wattage, both reef and plant.

Uhm, I did in the last post, I gave multiple plausible causes.

I reread, closely. Mostly "ain't it". Maybe I missed your
causes for your style.

You can believe want you want, you are still wrong.
Research shows this, I can show this in a plant tank, you can show
this to yourself in a planted tank.

Anecdotal, and the lake study is ill controlled.

The AGA contest winners, all the plant clubs have got it all wrong and
you are the only that's right?

Anecdotal.

Humm you might want to actually try it and see about this, maybe read
some of the references, ask around.

I live it. I limit P, provide high-light, dose PMDD, and
have very few problems with BGA/Algae. My plants out pace my
eagerness to prune, I surely care not to "improve" their
status any further.

Hey, you can believe what you want to believe, but your still wrong
about PO4.

Ain't it! Fine.

You have not supported your contentions, I have.

Eh?

References in science relevant to the topic. Examples in the hobby,
your own research etc. eg have you actually tried high PO4 in a
planted tank?
Add KH2PO4 etc......is it repeatable? Can we find many exmaples in
natural field studies as well?

Actually I have proven quite definitively that excess PO4 that is
available for both plants and algae equally, not not cause algal
blooms in planted tanks with good plant biomass, CO2, moderate-high
light, good dosing of the other nutrients.

Anecdotal. If I can limit via P (in the world where 0 means
0), or I can limit via Fe (also in world where 0 means 0),
or I can limit via "Factor X", then...

If I choose P, and you choose "Factor X" (knowingly, or
not), then by your science, you can "prove" P is "wrong" all
day long.

No, I ve measured PO4 uptake due directly to plants, not algae or
complexing, precipitation.
Why would plants remove it(some can be due to luxury uptake), there's
plenty for the algae to assimilate as well and yet there is no algae
biomass?

This is the observation and has been repeated for many years
now(Tropica, Oriential Aquarium amongst other growers of plants and
Florida has a huge aquatic plant industry and is where I live).
You can pick NO3, Fe, K+ etc, there's plenty for the algae and the
plants.

By limiting these nutrients, you select more for the algae than the
plants which have much larger nutrient requirements than algae.
Algae live in a much smaller environment and difference niches than
macrophytes.


If you want to talk about causual mechanisms, you need to be able to
isolate the issues and deal with PO4 in a controlled manner.

No, you have to deal with BGA in a controlled manner. PO4,
in science-pure water, won't support any form of life, at
all. You simply cannot control for P, alone, in the life
cycle of BGA.

I was not talking about just water and PO4.
I mentioned to control the other parameters, CO2, light, K+ etc and
vary just the PO4 alone.

Folks often have trouble doing this, they then blame the wrong
parameter such as PO4 rather than low CO2 near the end of the day or
low NO3 etc.
A chemostat does this but is tricky to use and get set up correctly.
Many pelagic algal studies use such a device.

Aquarist can do something close that will control reasonably well for
PO4 by knowing what their tap water(or RO water) contains and doing
large frequent water changes and dosing afterwards to maintain good
nutrients levels while varying the PO4.

Large frequent water changes keeps the nutrients from becoming too
highand the frequent dosing keep the nutrients from running out. In
this manner you can vary whatever nutrient you want to consider.

Many have done this and found this to be true with high PO4 levels up
to 2.0ppm.
Surely at 2.0ppm the algae are not limited, so something else is
keeping the algae at bay in planted tanks.

I suggested a number of papers to support this observation.
You might want to read these before coming back with nothing more than
banther and your own anecdotal comments.

Then you would have something to discuss about why lakes and rivers
with plants are clear and algal free and aquariums that also have high
PO4 levels.

You can argue that lakes are not like aquariums yet what you based
your studies on are also based on Northern lakes often with no/few
macrophytes relative to the lake's surface area.

If you have studies showing planted tanks produce more algae with
added PO4 vs limited PO4, please, let's see these studies or show some
data of some sort.

I found that the Chl a concentrations decreased in well planted tanks
with PO4 levels at 0.5-1.0ppm range over 4 weeks using glass slide
substrates(ref:EPA protocols) while plant biommass increased
dramtically. A tank control with PO4 limitation at less than 0.1 ppm
PO4 had 40% less plant biomass and increased algae(62% more algae vs
the PO4 enriched tank). Plant uptake was estimated at 0.3ppm per day
uptake in the high plant tank.

So what have you found?
I've reported the uptake rates in planted tanks for sometime
concerning PO4 and NO3 etc.

Regardless of lighting levels? You sure you want to say that?

Absolutely. I've never, ever, reduced lighting on the reef
tank.

So less light also? This is a plant list and I'll keep it confirmed to
this topic, reefs are not = to plants, they are critters, some have
algae, many don't. They can supply a great deal of their N and P from
the food they catch rather water column inorganic nutrient uptake.

Big difference. Now if you want to talk about a macroalgae/seagrass
bed in shallow water such as the Keys, things might be closer to being
a comparison.

Uhm, I did in the last post, I gave multiple plausible causes.

I reread, closely. Mostly "ain't it". Maybe I missed your
causes for your style.


Pruning, this removes the algae on the lower leaves.
Water changes, removes any algae scrubbed off from glass etc.
Fluffing plants and good current, remove a fair amount of
periphyton(See Zimba and Hopson)
Photorespiration in specific species of algae(Bowes, Madsen)
Light competition( also Bowes)
Algae sensing a good environment to grow(low Dissolved O2(microsites),
NH4)
Algae and macrophytes are in different Niches( Sand Jensen paper)

I did not see a single reference of any kind from you.

Still haven't except for Paul and Kevin anecdotal paper.

You can believe want you want, you are still wrong.
Research shows this, I can show this in a plant tank, you can show
this to yourself in a planted tank.

Anecdotal, and the lake study is ill controlled.

So someone that has not read the research and has not tried it, bases
their own contentions of anecdotal study by Paul/Kevin knows all about
it then?

Okayyyyyyy whatever

The AGA contest winners, all the plant clubs have got it all wrong and
you are the only that's right?

Anecdotal.

Is a large pattern and highly experienced group all wrong?
If I can achieve high levels of health and growth with high PO4, and
is repeatable with many other people incorrect and we are assuming too
much here?
Why are some lakes also similar with similar observations?
I guess they are all wrong and you are right?

If I were you, I'd be questioning my arguements.

Humm you might want to actually try it and see about this, maybe read
some of the references, ask around.

I live it.

So do I, but.......I also try different things such as adding NH4, PO4
etc and control the other parameters, I cite and support my arguements
and these also support the observations. You?

I limit P, provide high-light, dose PMDD, and
have very few problems with BGA/Algae. My plants out pace my
eagerness to prune, I surely care not to "improve" their
status any further.

Let's have something to compare it against.

You apparently only know PO4 limited systems, if by adding PO4 to this
system, you see an improvement with aquatic plants and no algae or
less algae, what would you think then?

What types of PO4 levels are we talking about here?

In order to limit BGA/algae growth, you need to get below 0.005ppm of
PO4, see Ulrich's paper among others.

This has been my contention all along, the needs of the plants are
larger than that of the algae.

N:P ratios for aquatic macrophytes are around 10:1 and for FW algae
about 14:1.
Adding PO4 will favor the plants when both are present rather than
limiting it.

Like I've been saying, try it out since you don't believe me, I've
tried the PO4 limited approaches in the past also. I know both sides
of this coin.

Since you seem concerned about empirical data, I've given a large
number of papers to peruse on aquatic plant and algae ecology and
physiology, have done my own research and given some actual data
yet........you've provided none to support your own "anecdotal"
arguement.

If you want to ask for citations fine, but if you do not read them,
don't ask for more

Regards,
Tom Barr

You have not supported your contentions, I have.

Eh?

References in science relevant to the topic. Examples in the hobby,
your own research etc. eg have you actually tried high PO4 in a
planted tank?
Add KH2PO4 etc......is it repeatable? Can we find many exmaples in
natural field studies as well?

Actually I have proven quite definitively that excess PO4 that is
available for both plants and algae equally, not not cause algal
blooms in planted tanks with good plant biomass, CO2, moderate-high
light, good dosing of the other nutrients.

Anecdotal. If I can limit via P (in the world where 0 means
0), or I can limit via Fe (also in world where 0 means 0),
or I can limit via "Factor X", then...

If I choose P, and you choose "Factor X" (knowingly, or
not), then by your science, you can "prove" P is "wrong" all
day long.

No, I ve measured PO4 uptake due directly to plants, not algae or
complexing, precipitation.
Why would plants remove it(some can be due to luxury uptake), there's
plenty for the algae to assimilate as well and yet there is no algae
biomass?

This is the observation and has been repeated for many years
now(Tropica, Oriential Aquarium amongst other growers of plants and
Florida has a huge aquatic plant industry and is where I live).
You can pick NO3, Fe, K+ etc, there's plenty for the algae and the
plants.

By limiting these nutrients, you select more for the algae than the
plants which have much larger nutrient requirements than algae.
Algae live in a much smaller environment and difference niches than
macrophytes.


If you want to talk about causual mechanisms, you need to be able to
isolate the issues and deal with PO4 in a controlled manner.

No, you have to deal with BGA in a controlled manner. PO4,
in science-pure water, won't support any form of life, at
all. You simply cannot control for P, alone, in the life
cycle of BGA.

I was not talking about just water and PO4.
I mentioned to control the other parameters, CO2, light, K+ etc and
vary just the PO4 alone.

Folks often have trouble doing this, they then blame the wrong
parameter such as PO4 rather than low CO2 near the end of the day or
low NO3 etc.
A chemostat does this but is tricky to use and get set up correctly.
Many pelagic algal studies use such a device.

Aquarist can do something close that will control reasonably well for
PO4 by knowing what their tap water(or RO water) contains and doing
large frequent water changes and dosing afterwards to maintain good
nutrients levels while varying the PO4.

Large frequent water changes keeps the nutrients from becoming too
highand the frequent dosing keep the nutrients from running out. In
this manner you can vary whatever nutrient you want to consider.

Many have done this and found this to be true with high PO4 levels up
to 2.0ppm.
Surely at 2.0ppm the algae are not limited, so something else is
keeping the algae at bay in planted tanks.

I suggested a number of papers to support this observation.
You might want to read these before coming back with nothing more than
banther and your own anecdotal comments.

Then you would have something to discuss about why lakes and rivers
with plants are clear and algal free and aquariums that also have high
PO4 levels.

You can argue that lakes are not like aquariums yet what you based
your studies on are also based on Northern lakes often with no/few
macrophytes relative to the lake's surface area.

If you have studies showing planted tanks produce more algae with
added PO4 vs limited PO4, please, let's see these studies or show some
data of some sort.

I found that the Chl a concentrations decreased in well planted tanks
with PO4 levels at 0.5-1.0ppm range over 4 weeks using glass slide
substrates(ref:EPA protocols) while plant biommass increased
dramtically. A tank control with PO4 limitation at less than 0.1 ppm
PO4 had 40% less plant biomass and increased algae(62% more algae vs
the PO4 enriched tank). Plant uptake was estimated at 0.3ppm per day
uptake in the high plant tank.

So what have you found?
I've reported the uptake rates in planted tanks for sometime
concerning PO4 and NO3 etc.

Regardless of lighting levels? You sure you want to say that?

Absolutely. I've never, ever, reduced lighting on the reef
tank.

So less light also? This is a plant list and I'll keep it confirmed to
this topic, reefs are not = to plants, they are critters, some have
algae, many don't. They can supply a great deal of their N and P from
the food they catch rather water column inorganic nutrient uptake.

Big difference. Now if you want to talk about a macroalgae/seagrass
bed in shallow water such as the Keys, things might be closer to being
a comparison.

Uhm, I did in the last post, I gave multiple plausible causes.

I reread, closely. Mostly "ain't it". Maybe I missed your
causes for your style.


Pruning, this removes the algae on the lower leaves.
Water changes, removes any algae scrubbed off from glass etc.
Fluffing plants and good current, remove a fair amount of
periphyton(See Zimba and Hopson)
Photorespiration in specific species of algae(Bowes, Madsen)
Light competition( also Bowes)
Algae sensing a good environment to grow(low Dissolved O2(microsites),
NH4)
Algae and macrophytes are in different Niches( Sand Jensen paper)

I did not see a single reference of any kind from you.

Still haven't except for Paul and Kevin anecdotal paper.

You can believe want you want, you are still wrong.
Research shows this, I can show this in a plant tank, you can show
this to yourself in a planted tank.

Anecdotal, and the lake study is ill controlled.

So someone that has not read the research and has not tried it, bases
their own contentions of anecdotal study by Paul/Kevin knows all about
it then?

Okayyyyyyy whatever

The AGA contest winners, all the plant clubs have got it all wrong and
you are the only that's right?

Anecdotal.

Is a large pattern and highly experienced group all wrong?
If I can achieve high levels of health and growth with high PO4, and
is repeatable with many other people incorrect and we are assuming too
much here?
Why are some lakes also similar with similar observations?
I guess they are all wrong and you are right?

If I were you, I'd be questioning my arguements.

Humm you might want to actually try it and see about this, maybe read
some of the references, ask around.

I live it.

So do I, but.......I also try different things such as adding NH4, PO4
etc and control the other parameters, I cite and support my arguements
and these also support the observations. You?

I limit P, provide high-light, dose PMDD, and
have very few problems with BGA/Algae. My plants out pace my
eagerness to prune, I surely care not to "improve" their
status any further.

Let's have something to compare it against.

You apparently only know PO4 limited systems, if by adding PO4 to this
system, you see an improvement with aquatic plants and no algae or
less algae, what would you think then?

What types of PO4 levels are we talking about here?

In order to limit BGA/algae growth, you need to get below 0.005ppm of
PO4, see Ulrich's paper among others.

This has been my contention all along, the needs of the plants are
larger than that of the algae.

N:P ratios for aquatic macrophytes are around 10:1 and for FW algae
about 14:1.
Adding PO4 will favor the plants when both are present rather than
limiting it.

Like I've been saying, try it out since you don't believe me, I've
tried the PO4 limited approaches in the past also. I know both sides
of this coin.

Since you seem concerned about empirical data, I've given a large
number of papers to peruse on aquatic plant and algae ecology and
physiology, have done my own research and given some actual data
yet........you've provided none to support your own "anecdotal"
arguement.

If you want to ask for citations fine, but if you do not read them,
don't ask for more

Regards,
Tom Barr

You have not supported your contentions, I have.

Eh?

References in science relevant to the topic. Examples in the hobby,
your own research etc. eg have you actually tried high PO4 in a
planted tank?
Add KH2PO4 etc......is it repeatable? Can we find many exmaples in
natural field studies as well?

Actually I have proven quite definitively that excess PO4 that is
available for both plants and algae equally, not not cause algal
blooms in planted tanks with good plant biomass, CO2, moderate-high
light, good dosing of the other nutrients.

Anecdotal. If I can limit via P (in the world where 0 means
0), or I can limit via Fe (also in world where 0 means 0),
or I can limit via "Factor X", then...

If I choose P, and you choose "Factor X" (knowingly, or
not), then by your science, you can "prove" P is "wrong" all
day long.

No, I ve measured PO4 uptake due directly to plants, not algae or
complexing, precipitation.
Why would plants remove it(some can be due to luxury uptake), there's
plenty for the algae to assimilate as well and yet there is no algae
biomass?

This is the observation and has been repeated for many years
now(Tropica, Oriential Aquarium amongst other growers of plants and
Florida has a huge aquatic plant industry and is where I live).
You can pick NO3, Fe, K+ etc, there's plenty for the algae and the
plants.

By limiting these nutrients, you select more for the algae than the
plants which have much larger nutrient requirements than algae.
Algae live in a much smaller environment and difference niches than
macrophytes.


If you want to talk about causual mechanisms, you need to be able to
isolate the issues and deal with PO4 in a controlled manner.

No, you have to deal with BGA in a controlled manner. PO4,
in science-pure water, won't support any form of life, at
all. You simply cannot control for P, alone, in the life
cycle of BGA.

I was not talking about just water and PO4.
I mentioned to control the other parameters, CO2, light, K+ etc and
vary just the PO4 alone.

Folks often have trouble doing this, they then blame the wrong
parameter such as PO4 rather than low CO2 near the end of the day or
low NO3 etc.
A chemostat does this but is tricky to use and get set up correctly.
Many pelagic algal studies use such a device.

Aquarist can do something close that will control reasonably well for
PO4 by knowing what their tap water(or RO water) contains and doing
large frequent water changes and dosing afterwards to maintain good
nutrients levels while varying the PO4.

Large frequent water changes keeps the nutrients from becoming too
highand the frequent dosing keep the nutrients from running out. In
this manner you can vary whatever nutrient you want to consider.

Many have done this and found this to be true with high PO4 levels up
to 2.0ppm.
Surely at 2.0ppm the algae are not limited, so something else is
keeping the algae at bay in planted tanks.

I suggested a number of papers to support this observation.
You might want to read these before coming back with nothing more than
banther and your own anecdotal comments.

Then you would have something to discuss about why lakes and rivers
with plants are clear and algal free and aquariums that also have high
PO4 levels.

You can argue that lakes are not like aquariums yet what you based
your studies on are also based on Northern lakes often with no/few
macrophytes relative to the lake's surface area.

If you have studies showing planted tanks produce more algae with
added PO4 vs limited PO4, please, let's see these studies or show some
data of some sort.

I found that the Chl a concentrations decreased in well planted tanks
with PO4 levels at 0.5-1.0ppm range over 4 weeks using glass slide
substrates(ref:EPA protocols) while plant biommass increased
dramtically. A tank control with PO4 limitation at less than 0.1 ppm
PO4 had 40% less plant biomass and increased algae(62% more algae vs
the PO4 enriched tank). Plant uptake was estimated at 0.3ppm per day
uptake in the high plant tank.

So what have you found?
I've reported the uptake rates in planted tanks for sometime
concerning PO4 and NO3 etc.

Regardless of lighting levels? You sure you want to say that?

Absolutely. I've never, ever, reduced lighting on the reef
tank.

So less light also? This is a plant list and I'll keep it confirmed to
this topic, reefs are not = to plants, they are critters, some have
algae, many don't. They can supply a great deal of their N and P from
the food they catch rather water column inorganic nutrient uptake.

Big difference. Now if you want to talk about a macroalgae/seagrass
bed in shallow water such as the Keys, things might be closer to being
a comparison.

Uhm, I did in the last post, I gave multiple plausible causes.

I reread, closely. Mostly "ain't it". Maybe I missed your
causes for your style.


Pruning, this removes the algae on the lower leaves.
Water changes, removes any algae scrubbed off from glass etc.
Fluffing plants and good current, remove a fair amount of
periphyton(See Zimba and Hopson)
Photorespiration in specific species of algae(Bowes, Madsen)
Light competition( also Bowes)
Algae sensing a good environment to grow(low Dissolved O2(microsites),
NH4)
Algae and macrophytes are in different Niches( Sand Jensen paper)

I did not see a single reference of any kind from you.

Still haven't except for Paul and Kevin anecdotal paper.

You can believe want you want, you are still wrong.
Research shows this, I can show this in a plant tank, you can show
this to yourself in a planted tank.

Anecdotal, and the lake study is ill controlled.

So someone that has not read the research and has not tried it, bases
their own contentions of anecdotal study by Paul/Kevin knows all about
it then?

Okayyyyyyy whatever

The AGA contest winners, all the plant clubs have got it all wrong and
you are the only that's right?

Anecdotal.

Is a large pattern and highly experienced group all wrong?
If I can achieve high levels of health and growth with high PO4, and
is repeatable with many other people incorrect and we are assuming too
much here?
Why are some lakes also similar with similar observations?
I guess they are all wrong and you are right?

If I were you, I'd be questioning my arguements.

Humm you might want to actually try it and see about this, maybe read
some of the references, ask around.

I live it.

So do I, but.......I also try different things such as adding NH4, PO4
etc and control the other parameters, I cite and support my arguements
and these also support the observations. You?

I limit P, provide high-light, dose PMDD, and
have very few problems with BGA/Algae. My plants out pace my
eagerness to prune, I surely care not to "improve" their
status any further.

Let's have something to compare it against.

You apparently only know PO4 limited systems, if by adding PO4 to this
system, you see an improvement with aquatic plants and no algae or
less algae, what would you think then?

What types of PO4 levels are we talking about here?

In order to limit BGA/algae growth, you need to get below 0.005ppm of
PO4, see Ulrich's paper among others.

This has been my contention all along, the needs of the plants are
larger than that of the algae.

N:P ratios for aquatic macrophytes are around 10:1 and for FW algae
about 14:1.
Adding PO4 will favor the plants when both are present rather than
limiting it.

Like I've been saying, try it out since you don't believe me, I've
tried the PO4 limited approaches in the past also. I know both sides
of this coin.

Since you seem concerned about empirical data, I've given a large
number of papers to peruse on aquatic plant and algae ecology and
physiology, have done my own research and given some actual data
yet........you've provided none to support your own "anecdotal"
arguement.

If you want to ask for citations fine, but if you do not read them,
don't ask for more

Regards,
Tom Barr

You have not supported your contentions, I have.

Eh?

References in science relevant to the topic. Examples in the hobby,
your own research etc. eg have you actually tried high PO4 in a
planted tank?
Add KH2PO4 etc......is it repeatable? Can we find many exmaples in
natural field studies as well?

Actually I have proven quite definitively that excess PO4 that is
available for both plants and algae equally, not not cause algal
blooms in planted tanks with good plant biomass, CO2, moderate-high
light, good dosing of the other nutrients.

Anecdotal. If I can limit via P (in the world where 0 means
0), or I can limit via Fe (also in world where 0 means 0),
or I can limit via "Factor X", then...

If I choose P, and you choose "Factor X" (knowingly, or
not), then by your science, you can "prove" P is "wrong" all
day long.

No, I ve measured PO4 uptake due directly to plants, not algae or
complexing, precipitation.
Why would plants remove it(some can be due to luxury uptake), there's
plenty for the algae to assimilate as well and yet there is no algae
biomass?

This is the observation and has been repeated for many years
now(Tropica, Oriential Aquarium amongst other growers of plants and
Florida has a huge aquatic plant industry and is where I live).
You can pick NO3, Fe, K+ etc, there's plenty for the algae and the
plants.

By limiting these nutrients, you select more for the algae than the
plants which have much larger nutrient requirements than algae.
Algae live in a much smaller environment and difference niches than
macrophytes.


If you want to talk about causual mechanisms, you need to be able to
isolate the issues and deal with PO4 in a controlled manner.

No, you have to deal with BGA in a controlled manner. PO4,
in science-pure water, won't support any form of life, at
all. You simply cannot control for P, alone, in the life
cycle of BGA.

I was not talking about just water and PO4.
I mentioned to control the other parameters, CO2, light, K+ etc and
vary just the PO4 alone.

Folks often have trouble doing this, they then blame the wrong
parameter such as PO4 rather than low CO2 near the end of the day or
low NO3 etc.
A chemostat does this but is tricky to use and get set up correctly.
Many pelagic algal studies use such a device.

Aquarist can do something close that will control reasonably well for
PO4 by knowing what their tap water(or RO water) contains and doing
large frequent water changes and dosing afterwards to maintain good
nutrients levels while varying the PO4.

Large frequent water changes keeps the nutrients from becoming too
highand the frequent dosing keep the nutrients from running out. In
this manner you can vary whatever nutrient you want to consider.

Many have done this and found this to be true with high PO4 levels up
to 2.0ppm.
Surely at 2.0ppm the algae are not limited, so something else is
keeping the algae at bay in planted tanks.

I suggested a number of papers to support this observation.
You might want to read these before coming back with nothing more than
banther and your own anecdotal comments.

Then you would have something to discuss about why lakes and rivers
with plants are clear and algal free and aquariums that also have high
PO4 levels.

You can argue that lakes are not like aquariums yet what you based
your studies on are also based on Northern lakes often with no/few
macrophytes relative to the lake's surface area.

If you have studies showing planted tanks produce more algae with
added PO4 vs limited PO4, please, let's see these studies or show some
data of some sort.

I found that the Chl a concentrations decreased in well planted tanks
with PO4 levels at 0.5-1.0ppm range over 4 weeks using glass slide
substrates(ref:EPA protocols) while plant biommass increased
dramtically. A tank control with PO4 limitation at less than 0.1 ppm
PO4 had 40% less plant biomass and increased algae(62% more algae vs
the PO4 enriched tank). Plant uptake was estimated at 0.3ppm per day
uptake in the high plant tank.

So what have you found?
I've reported the uptake rates in planted tanks for sometime
concerning PO4 and NO3 etc.

Regardless of lighting levels? You sure you want to say that?

Absolutely. I've never, ever, reduced lighting on the reef
tank.

So less light also? This is a plant list and I'll keep it confirmed to
this topic, reefs are not = to plants, they are critters, some have
algae, many don't. They can supply a great deal of their N and P from
the food they catch rather water column inorganic nutrient uptake.

Big difference. Now if you want to talk about a macroalgae/seagrass
bed in shallow water such as the Keys, things might be closer to being
a comparison.

Uhm, I did in the last post, I gave multiple plausible causes.

I reread, closely. Mostly "ain't it". Maybe I missed your
causes for your style.


Pruning, this removes the algae on the lower leaves.
Water changes, removes any algae scrubbed off from glass etc.
Fluffing plants and good current, remove a fair amount of
periphyton(See Zimba and Hopson)
Photorespiration in specific species of algae(Bowes, Madsen)
Light competition( also Bowes)
Algae sensing a good environment to grow(low Dissolved O2(microsites),
NH4)
Algae and macrophytes are in different Niches( Sand Jensen paper)

I did not see a single reference of any kind from you.

Still haven't except for Paul and Kevin anecdotal paper.

You can believe want you want, you are still wrong.
Research shows this, I can show this in a plant tank, you can show
this to yourself in a planted tank.

Anecdotal, and the lake study is ill controlled.

So someone that has not read the research and has not tried it, bases
their own contentions of anecdotal study by Paul/Kevin knows all about
it then?

Okayyyyyyy whatever

The AGA contest winners, all the plant clubs have got it all wrong and
you are the only that's right?

Anecdotal.

Is a large pattern and highly experienced group all wrong?
If I can achieve high levels of health and growth with high PO4, and
is repeatable with many other people incorrect and we are assuming too
much here?
Why are some lakes also similar with similar observations?
I guess they are all wrong and you are right?

If I were you, I'd be questioning my arguements.

Humm you might want to actually try it and see about this, maybe read
some of the references, ask around.

I live it.

So do I, but.......I also try different things such as adding NH4, PO4
etc and control the other parameters, I cite and support my arguements
and these also support the observations. You?

I limit P, provide high-light, dose PMDD, and
have very few problems with BGA/Algae. My plants out pace my
eagerness to prune, I surely care not to "improve" their
status any further.

Let's have something to compare it against.

You apparently only know PO4 limited systems, if by adding PO4 to this
system, you see an improvement with aquatic plants and no algae or
less algae, what would you think then?

What types of PO4 levels are we talking about here?

In order to limit BGA/algae growth, you need to get below 0.005ppm of
PO4, see Ulrich's paper among others.

This has been my contention all along, the needs of the plants are
larger than that of the algae.

N:P ratios for aquatic macrophytes are around 10:1 and for FW algae
about 14:1.
Adding PO4 will favor the plants when both are present rather than
limiting it.

Like I've been saying, try it out since you don't believe me, I've
tried the PO4 limited approaches in the past also. I know both sides
of this coin.

Since you seem concerned about empirical data, I've given a large
number of papers to peruse on aquatic plant and algae ecology and
physiology, have done my own research and given some actual data
yet........you've provided none to support your own "anecdotal"
arguement.

If you want to ask for citations fine, but if you do not read them,
don't ask for more

Regards,
Tom Barr