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150 ppm co2?

Now this I agree with. My pH drop is 1.4. What is my actual CO2 level? Who knows. The charts would say well over a hundred. Is it really? Not likely.
I usually keep my ph drop around that 1.3 1.4 marks, but lately i decided to test out what it could do if i push it further more so i have increased it slowly over weeks, months to about 1.8 drop. I haven't seen improvement what so ever in growth. Could be that i didn't not have enough light to drive it or something.
 
I'll stick my hand up and be the lonely voice in favour of drop checkers.

With experience a quick glance at my drop checker tells me straight away if I'm hitting the right CO2 levels for my tank. It tells me visually every day if increasing plant mass, or reduced/increase surface agitation has altered the CO2 levels. It even alerts me when my CO2 bottle runs out if I haven't checked the gauges in a while. It also allows me to test measure any point in the tank for distribution issues.

Whilst measuring the pH drop is for sure a good method, for setting initial CO2, and gives an instant reading rather than the drop checkers time delay, it's still fraught with issues. Most aquarists don't stump up for a pH meter with wired probes, and are therefore limited to measuring pH with a integrated hand held meter that can only measure in the top 75mm of water. In my experience with a good quality and accurate pH probe, pH can vary around the tank significantly, in line with CO2 distribution, so is caught with similar location issues to the drop checker in that respect. It's also very labour intensive to take a manual pH profile if you don't have a more expensive data logging probe.

For me setting up a new tank is also easy with the drop checker - I start with slightly over-egging the input rate to get a colour verging on yellow, and then back it off gradually until I hit the right level. I can usually get to the right point within a couple of days, which is far easier and less labour intensive than running consecutive manual pH profiles (even though my probe is a data logging type).

Don't get me wrong, I think the committed aquarist should both tools in their arsenal, but I find with experience I rely on the drop checker much more.
 
I usually keep my ph drop around that 1.3 1.4 marks, but lately i decided to test out what it could do if i push it further more so i have increased it slowly over weeks, months to about 1.8 drop. I haven't seen improvement what so ever in growth. Could be that i didn't not have enough light to drive it or something.
Many I know have tested this theory over the years and have found it subject to the law of diminishing returns. Once you get to to a certain level plants have all they can possibly uptake and the extra is wasted.

I'll stick my hand up and be the lonely voice in favour of drop checkers.
It all depends on how precise you want to be and your level of ambition. Keep in mind a drop checker is nothing more than a liquid pH test.

I have tested liquid pH tests against good quality calibrated probes and they can be off quite a bit. I adjust my pH drop up/down in 0.05 increments which would be impossible with a drop checker.

But in the scheme of things if you just want "good" CO2 a drop checker will work just fine. If you really want to optimize CO2 a calibrated good quality probe is best. Of the great tanks that I follow I can't think of one that uses a drop checker, but then again their ambition is greater than the average tank.
 
I'm also on board with the drop checker. Totally idiot-proof and you just look at it to see where you are. People that think they can meaningfully optimise CO2 by measuring pH in 0.05 unit increments are fooling themselves, but if they enjoy doing it that also has value. ;)
LOL I do enjoy the process.

And I did mention tuning in 0.05 increments. Let me explain that.

Let's say my current drop is to 5.00 pH. To fine tune I start by dropping to 4.95. Then observe plants and fish for a few days. Then down to 4.90 and do the same. And then again until I hit the point where plants are pearling and happy and fish show no signs of discomfort.

You may think there is no difference if CO2 is optimized, but in my experience it's easily the best thing most folks could do to increase their success in the hobby. Playing whack-a-mole ferts rarely works, but fine tuning CO2 brings immediate results. But again all depends on one's ambitions in the hobby.
 
In fact, terrestrial plants worldwide are starving for more carbon because of critically low atmospheric CO2 levels. We have ~ 400 ppm now thanks to burning fossil fuels for the last 120 years. It was as low as 300 ppm 120 years ago and it was like this for thousands of years, dropping down to critical level for plants to trive. The best time plants had it was when CO2 level in atmosphere was up to 8 000 ppm, 20 x more than today, it was millions of years ago. That's when ferns grew as large as trees. CO2 molecule is one of the most important molecules keeping this planet alive, CO2 is a molecule of life.
Here is a research paper to show how low CO2 atmospheric levels are at the present time, in fact it is so low that plants cannot grow to full potential. And, we won’t see this on TV for some bizarre reason.

CO2 sequestration in plants: lesson from divergent strategies, pages 481–496 (2011), S. K. Vats, S. Kumar, P. S. Ahuja in Photosynthetica (2011)

“Most organisms inhabiting earth feed directly or indirectly on the products synthesized by the reaction of photosynthesis, which at the current atmospheric CO2 levels operates only at two thirds of its peak efficiency. Restricting the photorespiratory loss of carbon and thereby improving the efficiency of photosynthesis is seen by many as a good option to enhance productivity of food crops. Research during last half a century has shown that several plant species developed CO2-concentrating mechanism (CCM) to restrict photorespiration under lower concentration of available CO2. CCMs are now known to be operative in several terrestrial and aquatic plants, ranging from most advanced higher plants to algae, cyanobacteria and diatoms. Plants with C4 pathway of photosynthesis (where four-carbon compound is the first product of photosynthesis) or crassulacean acid metabolism (CAM) may consistently operate CCM. Some plants however can undergo a shift in photosynthetic metabolism only with change in environmental variables. More recently, a shift in plant photosynthetic metabolism is reported at high altitude where improved efficiency of CO2 uptake is related to the recapture of photorespiratory loss of carbon. Of the divergent CO2 assimilation strategies operative in different oraganisms, the capacity to recapture photorespiratory CO2 could be an important approach to develop plants with efficient photosynthetic capacity.”

 
Please share such research. Always willing to learn more.
Curious what research is this?
This research paper talks about higher CO2 levels inhibiting aquatic plant growth. Who would have thought?

“The critical values of CO2 lay approximately between 0.6 to 1.0 mM (26 to 44 ppm CO2). At this critical CO2 concentration photosynthetic rate reached its maximum and then decreased with increasing CO2.”

1 mM = 44 ppm CO2


 
This research paper talks about higher CO2 levels inhibiting aquatic plant growth. Who would have thought?

“The critical values of CO2 lay approximately between 0.6 to 1.0 mM (26 to 44 ppm CO2). At this critical CO2 concentration photosynthetic rate reached its maximum and then decreased with increasing CO2.”

1 mM = 44 ppm CO2


The problem with scientific studies is that they may or may not haven anything to do with the species we grow and the way we grow them in glass boxes.

But either way the bigger issue is that folks have little idea what their actual CO2 levels are. It's an educated guess at best without the proper test equipment. So someone thinks they are perfect at 30 ppm, but the reality may be quite different.

In the long run the preciseness has little to do with keeping a great planted tank. Like most things in this hobby it's more about relative values.
 
The problem with scientific studies is that they may or may not haven anything to do with the species we grow and the way we grow them in glass boxes.

But either way the bigger issue is that folks have little idea what their actual CO2 levels are. It's an educated guess at best without the proper test equipment. So someone thinks they are perfect at 30 ppm, but the reality may be quite different.

In the long run the preciseness has little to do with keeping a great planted tank. Like most things in this hobby it's more about relative values.
Choosing to ignore the researched topic and stirring the discussion to insufficient number of studied plant species and glass box excuses?

The study is about high CO2 inhibiting aquatic plant growth. It has been observed and studied. And the study has demonstrated how higher CO2 levels can be detrimental to aquatic plants. Levels of 30 ppm and higher, recommended by some, can actually be causing more harm than good this study suggests.

I kind of expect, though it takes time, to see posts like, Full CO2, 1/2 CO2 and 1/4 CO2, to gain popularity.
 
The threadstarter MrTank says he has 9 different tanks, some tanks appear to have 30pm-40ppm, and he also has this special tank with 150ppm CO2.
Assuming that the other tank parameters are roughly the same and the major difference is the CO2 levels, then we can see for ourselves the difference between 150ppm CO2 and 30-40ppm CO2 once he posts photos of his tanks.. He can also share with us his own observations on how 150ppm CO2 has affected plant growth.

Even if it is not actually 150ppm, I presume he is pumping into that tank a whole lot more CO2 compared to the other tanks where he has 30-40ppm CO2, so we can still look at the difference between 30-40ppm and a whole lot more (even if not 150ppm)....
 
Choosing to ignore the researched topic and stirring the discussion to insufficient number of studied plant species and glass box excuses?

The study is about high CO2 inhibiting aquatic plant growth. It has been observed and studied. And the study has demonstrated how higher CO2 levels can be detrimental to aquatic plants. Levels of 30 ppm and higher, recommended by some, can actually be causing more harm than good this study suggests.

I kind of expect, though it takes time, to see posts like, Full CO2, 1/2 CO2 and 1/4 CO2, to gain popularity.
Observed and studied? In an aquarium? Not even close. What does any of your arguments have to do with presenting a planted tank that someone would aspire to? IMO you may not be able to see the forest through the trees.

Arguing about levels of CO2 that can only be measured in a lab have little to do with growing plants in an aquarium.

And I am sorry I am not familiar with you. Can you show me something you have created that I would be interested in learning more about? I am eager to learn from those that are successful in growing plants. Show me something and it would be a more interesting discussion.
 
And I am sorry I am not familiar with you. Can you show me something you have created that I would be interested in learning more about? I am eager to learn from those that are successful in growing plants. Show me something and it would be a more interesting discussion.
With all due respect, how do we as a community know for sure, you are not taking pictures of your neighbour's tank? You know, as far as internet credibility goes.
 
This research paper talks about higher CO2 levels inhibiting aquatic plant growth. Who would have thought?

“The critical values of CO2 lay approximately between 0.6 to 1.0 mM (26 to 44 ppm CO2). At this critical CO2 concentration photosynthetic rate reached its maximum and then decreased with increasing CO2.”

1 mM = 44 ppm CO2

Choosing to ignore the researched topic and stirring the discussion to insufficient number of studied plant species and glass box excuses?

The study is about high CO2 inhibiting aquatic plant growth. It has been observed and studied. And the study has demonstrated how higher CO2 levels can be detrimental to aquatic plants. Levels of 30 ppm and higher, recommended by some, can actually be causing more harm than good this study suggests.

I kind of expect, though it takes time, to see posts like, Full CO2, 1/2 CO2 and 1/4 CO2, to gain popularity.
I read the abstract and the results of that study and tried to understand as much as I could considering I am no biologist. Let's get things straight here for a moment. The study does not talk about 'higher CO2 levels inhibiting aquatic plant growth'. It talks very specifically about Elodena densa, not "plants". Full stop. So you claiming that 30 ppm or so of CO2 inhibits plants growth in general terms is a huge extrapolation of facts discussed in that paper. In fact that plant has been known for a long time to be a low CO2 demanding plant which actually does much better with low CO2 levels than with higher levels. This is definitely not the case for most plants we grow in aquariums. This plant has been discussed in the forum. Even for slow growing plants which would do fine with lower CO2 disponilility benefit from additional CO2. I am not making any claims here, just pointing out that making generalities like the one you did is a no no.
With all due respect, how do we as a community know for sure, you are not taking pictures of your neighbour's tank? You know, as far as internet credibility goes.
All is possible. Clearly you have no clue though. Because I don't want to be labeled a Gregg fanboy I simply did a quick google search to show it's at anyone's fingertips. Maybe with today's technology deep fakes are possible though 😚

I guess all those respected people and companies have a conspiracy going on. @GreggZ Where's the pic with you and a guy in front of your tank BTW? Couldn't find it. Did people found out it was photoshoped and you deleted it from the internet?
 
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With all due respect, how do we as a community know for sure, you are not taking pictures of your neighbour's tank? You know, as far as internet credibility goes.
I guess I should have expected this argument based on who's methodology you favor. It's the same excuse I have heard from that camp for a decade. It's like they have a school that teaches it.

In the end, this is a visual hobby. All the people I know and communicate with share pictures all the time. It's the best tool we have to share results.


Where's the pic with you and a guy in front of your tank BTW? Couldn't find it. Did people found out it was photoshoped and you deleted it from the internet?
Don't be fooled. He's not real. I created a deep fake. Same for all the 1,000's of other pictures I have posted over a very long time. I have a cottage industry going on here creating fake pictures.😄😄
20210130_151530.jpg
 
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Hi all,
I think it's something like vapor pressure / partial pressure x 10^6 = ppm. Probably wrong... but looping in @dw1305 as Darrel probably knows this.
Unfortunately not, I don't have access to Nature as a journal. I think the reason for the fluctuating CO2 levels is to do with the dry and wet seasons in the Amazon basin.
The study is about high CO2 inhibiting aquatic plant growth.
I think the issue for us is that most of the plants we grow aren't really obligate aquatic plants (without a cuticle or stomata etc), but they are semi-aquatic emergent plants and they really want to get at the 420 ppm of atmospheric CO2.

cheers Darrel
 
I think the issue for us is that most of the plants we grow aren't really obligate aquatic plants (without a cuticle or stomata etc), but they are semi-aquatic emergent plants and they really want to get at the 420 ppm of atmospheric CO2.
Thank you @dw1305 for clarifying.
You call this plant category semi-aquatic. We have aquatic plants and non-aquatic plants, but what is a semi-aquatic plant? And also how can we tell what is real aquatic and what is not?
Thanks
 
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