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Phosphate is the king of the planted tank

JoshP12

Member
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8 Dec 2019
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Hi all,

I continually made this claim* that was followed by, "based on my readings, I think ..." or something along those lines.

After < learning a bit about photosynthesis >, I realized that my thought that *phosphate directly controls CO2 demand is actually true. When the < light-dependent reaction > of photosynthesis occurs, it converts ADP to ATP:
1595681525982.png
1595681577716.png

That's your phosphate.


The light-dependent reactions happen before the Calvin Cycle:
1595681626564.png


which use the ATP and uses the CO2.

Phosphate is used BEFORE CO2 ... hence phosphate drive CO2 need.

What drive phosphate consumption? Light.

What happens if we provide enough phosphate - but still limit it (and provide enough of the other nutrients) ... OR blast the tank with light
... ***the plants color changes:
... via:
... the plants finds a way to mitigate the amount of light they get
... they get light from the chlorophyll pigment
... find a way to break down < Pheophytin > which is the first element in the Electron Transport Chain from PS 1
... **break down < chlorophyll a leaving chlorophyll b > ... we deal with < mostly Chlorophyll A and B >:

There are four types of chlorophyll: chlorophyll a, found in all higher plants, algae and cyanobacteria; chlorophyll b, found in higher plants and green algae; chlorophyll c, found in diatoms, dinoflagellates and brown algae; and chlorophyll d, found only in red algae.

... all plants have carotenoids (red/orange/yellow pigment); we just can't see them, then*** when we **.

For the same reason, carotenoid colors often predominate in ripe fruit after being unmasked by the disappearance of chlorophyll**.

and ...

1) ****I am thinking nitrate limitation is actually phosphate limitation (with no nitrogen deficiency) ... and I conjecture that with high light, we could provide ample nitrates and limit phosphates and get colorations. This never happens - because aquarists doing this are meticulous cleaners, water changers, controllers, etc.
2) This is why people notice their nitrogen (and other nutrients) plummet if phosphates sky rocket
3) This is why < " phosphates cause algae " >
4) This is PMDD
5) This is why some people say stop dosing for a few days and see what happens, then they blame EI for their issues


*** I daily dose EI - nitrate is not 0, it isn't 5, it isn't 10.

Why:
1595683578504.png


Half the plants are ok, the other half aren't:
1595683630323.png


This is why we replant tops - and not the middle segment <-- I replanted those and guess what, they are struggling - they will be fine in a few weeks though.

I am bombarding the tank with light my AI primes are at 100%.

And I am giving ample phosphates to fuel ATP creation. They are scared - and they are turning color to slow down photosynthesis because they can't keep up. I bombard them with phosphates forcing them to grow via chemistry + physics (this is a cop out as it is probabilities/concentrations/and flow that determine the latter).

They do not have the RuBisCo concentration to absorb CO2 from my water column TO MATCH my forced phosphates, to perform carbon fixation, to make sugars, to build tissue ... hence why they are thin. They aren't stunted, they aren't any other deficiency. It is CO2. But because of phosphates. It also has other things - not just RuBisCo ... the thylakoid aren't stacked properly etc.

At this point, I am convinced that I can either:

1) reduce light (which is what I did this morning) ... because it is the click of a button.
2) Leave light and reduce phosphates (what I should do) - I did not do this because my doser has the macro solution already mixed.
3) Increase CO2 even more - and gas my fish -- which I have done in the past.

Notice that my Pogo is still healthy:
1595683929471.png

It has adapted to these conditions.

And one could argue that my rotala were already in my tank so they have adapted. But if we recall, they were 3x as tall. Amano suggested cutting 1/3 ONLY of a stem (read this from one of @alto's posts) ... and it is for this reason: it will reduce the likelihood that the plant itself does not have the proper configuration for the conditions it is in.

This is why < we should use low light on start up >.

So as per what @Ray said < here >, I think we can extend this notion to each internode of each stem as @Ray asserted < here >.

Hmm ... I guess that's all :D.

Please, please, please, if I am wrong on any of this, please correct me.

I am merely in a pursuit of understanding.

Josh
 
Yikes, @JoshP12

That's a lot to absorb. I wish I could usefully contribute to this thread but, when we start talking about RuBisCo, I'm out of my depth!

JPC
 
when we start talking about RuBisCo

My comments on RuBisCo were not meant to deter the focus of the thread. That comment was to explain why my plants had struggled with CO2 - and more importantly because of the phosphates that I bombard them with.

The point was that Phosphate is used before CO2. And phosphate is used after light. So Phosphate is the king. :p

Now, we have to make one assumption - that we are starting with a healthy leaf - FOR, if we did not have carbon to make that healthy leaf, then phosphate is not the king.

However and more truthfully - they are all the kings. I should perhaps re-name the thread as: phosphate is the king of photosynthesis ... but that's light GAH.

Phosphate is useful :).

Josh
 
Hi @JoshP12
I should perhaps re-name the thread as: phosphate is the king of photosynthesis ... but that's light GAH.

Ah, right. I'm with you now - except for one little acronym - GAH. Sorry, I scratched my head and also did a search for it. What is GAH?

JPC
 
Thanks for invoking me Josh :). It's 30 years since I sat in a classroom and looked at the ADP - ATP cycle (for A level biology) so I hadn't twigged that that was what the plants needed phosphate for - so thanks for that realisation! As far as I can tell you are correct.
The Amano advice to cut only 1/3 of a stem is very interesting. It's not what some of the guys on YouTube are doing but I think you're right to say if part of a stem grew at a different level in the tank to where it now it, it's at some kind of a disadvantage. If your conditions are borderline or the stem very demanding that may be a problem... I also found the Clive post you triggered in one of your links very interesting - that transitioning from emersed to submersed in nature it's likely the water will be turbid initially is something I had not thought of that sounds very reasonable.
 
It's not what some of the guys on YouTube are doing but I think you're right to say if part of a stem grew at a different level in the tank to where it now it, it's at some kind of a disadvantage.

Especially since my tank is 2 feet tall.

Hi @JoshP12


Ah, right. I'm with you now - except for one little acronym - GAH. Sorry, I scratched my head and also did a search for it. What is GAH?

JPC

I think he means “Gaaaah!!!

:p ... Yes like a "ahh! It's a cycle that never ends!"
 
What comes next is that CO2 does NOT need to be stable (the same CO2 concentration from lights on to lights off which is often decided by stable pH) from lights on.

I do not mean that the injection can fluctuate - that is bad news.

I mean that the CO2 concentration in the tank needs to match the rate of the light-dependent reaction. Specifically, the rate at which ATP and NADPH are being created - which is dictated by 2 things:
1) Light
2) Phosphate

The plant can deal with excess light by degenerated its chlorophyll.

Look:
1595695685336.png

He says to me, "how many chlorophyll are you going to make me destroy before you realize that you are pushing me to hard at my current state." Notice the entire new growth is gorgeous and colorful, but the old growth needs to be hit as well until the plant recovers.

This is what I experienced <here > attributing the coloration to a particular form of nitrate limitation - in fact, it was the plant transitioning, shielding itself temporarily, adjusting, then continuing its new growth. I did not continue that thread, but the plants would go back to green later. Intense red for a few days, then transition back.

So, actually, what I asked about < RuBisCo concentration depending on light or CO2 and the example I proposed > is correct.

In other words, the amount of CO2 required for healthy growth is a function of light (which is buffered by the plant) and phosphate concentration.

So, your concentration of CO2 simply needs to match you phosphate and light - it need not be stable. However, the stability solves problems because if the CO2 is in excess, we have no issues during the photoperiod. And it is much easier to just make it stable rather than < feel the tank >.

EI gives us the "maximum phosphate", so we are left with light driving photosynthesis.

The reason GSA goes away from increasing phosphates is from Mulders chart, nutrient accumulation, increasing probability that the plant can utilize phosphate, necessarily drive the calvin cycle and UTILIZE the CO2 in the system.

This picture is terrible and to my sadness I do not have a month ago. But I have not touched this buce leaf, moved him, cleaned him, whatever. The only thing I did was strip my system of < excess potassium> . The GSA and the fuzz algae on the edges has receded.
1595696541246.png


I suspect that those green thread algaes can be beat with the same concept.

Bottom line: CO2 concentration needs to match light + Phosphate throughout photoperiod. In theory, you could turn on CO2 with a HIGH injection rate, HIGH surface agitation, at lights on, WITH a gradual ramp up until your CO2 concentration reaches the appropriate value for your max light + phosphates.

Josh
 
your tank water may have plenty of PO4, but without flow the local [PO4] may be nothing if flow is low and high light next comes pin holes then melt ;)

In many ways, I think this idea shows why limiting phosphate is quite feasible in reducing CO2 demand on the tank. The idea would be not pump it full of excess phosphate, but to pump it with just enough.

I have not been to the ADA gallery, and I can't say that every single tank has SAE - but this shows that in the 10-15-20 zone (or 15-20-25 zone, I cannot find my reference) that is often quoted as the BBA growth zone, Amano can hold a tank at 20 and be algae free. Like I said, I don't know if he has SAE in every tank - and Amano shrimp could keep it at bay enough. BUT it does explain why I never see BBA in any lake. - rarely do these lakes have 30+ ppm of CO2. We know the water column of ADA has low phosphate and EI tanks have much higher levels.

Now, that ignores the ability for the PO4 to be pulled from the nutrient-packed substrate - however, moving that phosphate through the root system requires energy. It may be possible that the energy needed offsets the excess energy fueling the Calvin Cycle.

Not sure and cannot say much, but it has definitely got me thinking.

Josh
 
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Hi @JoshP12
So, your concentration of CO2 simply needs to match you phosphate and light - it need not be stable. However, the stability solves problems because if the CO2 is in excess, we have no issues during the photoperiod.

In order to put your interesting hypothesis to the test, we need some data. We need [CO2] in mg/l, [PO4] in mg/l and light (PPF*) in micromoles/sec. I think the light spectrum should also be measured over the accepted PAR** bandwidth (400nm -700nm). This is not an easy experiment to set up - but it's not impossible.

Or, you could run your thoughts past Dr Bruce Bugbee at Apogee Instruments? But, that may come at a price!

* PPF = photosynthetic photon flux

** PAR = photosynthetically active radiation

JPC
 
For this discussion, we can assume flow is sufficient

But Flow is still ruler of all, many experienced members have been stating in many threads Flow is King in a high tech tank in an attempt for others esp folk new to planted tanks don't underestimate the importance of good flow, the general principles of EI dosing is dose in excess so [PO4] is irrelevant, regular WC so DOC are irrelevant to some extent with good tank maintenance, good flow is critical for CO2 distribution in high light CO2 injected tanks.

But 'PO4 is king of the planted tank' is a nono o_O IMO, however 'PO4 is king of the Calvin cycle' on the other hand is fine and debatable IMO. The simplified Calvin cycle you have quoted is enough for most folks to switch off and still remember Flow is king

BUT it does explain why I never see BBA in any lake.

But what are the levels of Dissolved Organic Compounds ( DOC) in a Lake

CO2 concentration needs to match light + Phosphate throughout photoperiod

Liebig's law, even D Wong quotes Liebig with a portrait and has dropped the ratios of nutrients, everything in excess except toxins and the plants will outgrow the aglae, I have all types of algae in my tanks in small localised areas
 
Lesson: The Assh*le is usually the one in charge

All the organs of the body were having a meeting, trying to decide who was the one in charge.

"I should be in charge," said the brain, "because I run all the body's systems, so without me nothing would happen."

"I should be in charge," said the blood, "because I circulate oxygen all over so without me you'd waste away."

"I should be in charge," said the stomach, “because I process food and give all of you energy."

"I should be in charge," said the legs, "because I carry the body wherever it needs to go."

"I should be in charge," said the eyes, "because I allow the body to see where it goes."

"I should be in charge," said the rectum, "because I am responsible for waste removal."


All the other body parts laughed at the rectum and insulted him, so in a huff, he shut down tight.


Within a few days, the brain had a terrible headache, the stomach was bloated, the legs got wobbly, the eyes got watery, and the blood was toxic.


They all decided that the rectum should be the boss.



For the purposes of this exercise your scape design would be the assh*le in charge. It dictates all aspects of distribution and is unchanging unlike all the other things you can attempt to control for.
 
Hi all,

Apologies to everyone for the thread name - it does not reflect what I am trying to say properly.


But Flow is still ruler of all, many experienced members have been stating in many threads Flow is King in a high tech tank in an attempt for others esp folk new to planted tanks don't underestimate the importance of good flow,

I don't think anyone is denying that flow is important. But Flow without nutrients sucks.


the general principles of EI dosing is dose in excess so [PO4] is irrelevant, regular WC so DOC are irrelevant to some extent with good tank maintenance, good flow is critical for CO2 distribution in high light CO2 injected tanks.

We can't willy nilly dose everything as we please. The word excess is misleading. Too much of something will increase the chances that the plant will pick that up (possibly instead of something else? - Mulders). I love what Barr did to develop EI - it's great - and if it wasn't for EI, I would not know what healthy plants look like, nor would I have considered CO2 so deeply. But if you dump whatever the toxicity of something is in your tank (as it will be unique to each tank) minus 1 into your tank and sustain that level for months on end, there will be issues. My Rotala that changed almost immediately after MONTHS of excess potassium is a prime example. My Pogo too.

But 'PO4 is king of the planted tank' is a nono o_O IMO, however 'PO4 is king of the Calvin cycle' on the other hand is fine and debatable IMO. The simplified Calvin cycle you have quoted is enough for most folks to switch off and still remember Flow is king

RuBisCo (and NADPH) will have a conniption if you say that :p; Flow is king only when it carries nutrients - and of those nutrients, phosphate comes directly after light, and we put phosphates in - so if we can limit phosphates without starving the plant, then we should be able to reduce the demand on everything else in the tank. Sure dump in ferts (I do this), let stuff grow, WC, reset, voila - but we are missing something beautiful.

But what are the levels of Dissolved Organic Compounds ( DOC) in a Lake

Not sure, but when people have BBA, the most common response I read is to increase CO2/fix flow distribution. And then the quote that 15-25ish CO2 when everything else is in check spawns BBA. The answer is never to clean better.

CO2 and flow are important for a tank - no one is going to deny this.

Liebig's law, even D Wong quotes Liebig with a portrait and has dropped the ratios of nutrients, everything in excess except toxins and the plants will outgrow the aglae, I have all types of algae in my tanks in small localised areas

I did not refute Leigbig's ... I used it. We just need a bit more CO2 than is demanded in plant growth - and what dictates that plant growth is phosphates and light (which can be reflected by degenerating chlorophyll). This means, some combination of those two will dictate CO2 demand and it need not be the same "maximum" concentration from the beginning. Look at < this tank >.

Dennis Wong's website is wonderful and his tanks are gorgeous; however, he isn't going to dump 1 nutrient out of balance willy nilly - sure he can drop the notion of ratios (because really it is a probability game and in soft water there is so much less going on than hard) as those ratios have to be ratio-ranges. Further, D. Wong taught me a lot in his videos etc..


Lesson: The Assh*le is usually the one in charge

For the purposes of this exercise your scape design would be the assh*le in charge. It dictates all aspects of distribution and is unchanging unlike all the other things you can attempt to control for.

:D. Of course, but the scape design is meaningless without nutrients in the water.

This is why I put this thread under ferts.

The Assh*le of ferts is phosphate. Above all is light. But plants can reduce the light they absorb - phosphate is not so easy I don't think, especially when it flows by a leaf.

I do want to reiterate that I am simply learning about nutrients and plants.

I need to ensure that readers of this thread do know the importance of Flow and CO2 and scape design (which inherently dictates all else).

Josh
 
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Hi @JoshP12

In order to put your interesting hypothesis to the test, we need some data. We need [CO2] in mg/l, [PO4] in mg/l and light (PPF*) in micromoles/sec. I think the light spectrum should also be measured over the accepted PAR** bandwidth (400nm -700nm). This is not an easy experiment to set up - but it's not impossible.

Or, you could run your thoughts past Dr Bruce Bugbee at Apogee Instruments? But, that may come at a price!

* PPF = photosynthetic photon flux

** PAR = photosynthetically active radiation

JPC

Do we have examples on the forum of people who run successful tanks with less than 30 ppm (maybe 20?) co2 and a lean dosing regime and who ignore stability (stable from lights on to off, even if a ramp is in place)?

The complexity of substrate will come into play, however.

Josh
 
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