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Do you take the 1 pH drop from completely degassed water or from just before CO2 turns on?

KirstyF

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Unfortunately not kirsty. Different strokes for different folkes would be the correct and absolute answer.
There's 2 systems at work here.

The skilled observant edge cutting guy's that push the boundaries of our knowledge. We learn lots but they gas fish with CO2. Clive admits it, suspect barr has done it in the past.

The newbies that take it nice and slow (big ramp ups, low injection rate)... pros less likely to gas fish... cons may have unhealthy plants...

Newbies also gas fish, usually when they chase higher CO2 levels.

I would never push the boundaries on CO2 because my fish are paramount, others experiment, suspect their plants are the important bit 😉

Just my musings, cary on with the discussion...

Couldn’t agree with you more as regards fishies.

My first bash with Co2 dial in, prior to the first regulator fail - whacked up, tweaked a bit, sorted in a couple of days. Much the same 2nd time after I got it working again. 3rd time, with new regulator, has taken me nearly 2 weeks…..and I’ve left it at 0.9 drop, because now I have fishies and I’m mildly paranoid!

I also re-plumbed the tank cos they didn’t like the flow. 😂
 

KirstyF

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I think I’m all out of questions for now folks (Finally) or….at least until something else leaps to mind.

This has been very thought provoking and most enjoyable despite us not entirely reaching alignment on the rapid drop method 😊

@JacksonL

Also thanks again for allowing us to unashamedly hijack your thread. Hope you’ve enjoyed the ride so far!
 

JoshP12

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I’m kinda with you here at the moment. I’m just a bit like a terrier at a bone because there has to be an answer.

I guess if you tripled ur BPS (arbitrary number) you would hit 30ppm sooner? but the problem is, the ppm would then just keep climbing. My question to @JoshP12 is how would you then use or get rid of that Co2 to stop it from keep climbing? and whilst some extra uptake from higher light plants may use some Co2, it wouldn’t take up enough Co2 to allow that ‘tripling’ of BPS.
IMO of course 😊
@KirstyF As @Wookii stated, further increasing the injection rate would lead to a higher CO2 ppm. The equilibrium point will result from CO2 output (gas exchange + plant intake) and CO2 injection/input. If the starting point is a low light setup, then we have some room to nudge the equilibrium point by increasing the lights and therefore CO2 intake by the plants. But if the tank is already using strong lights then there is virtually no margin to offset the CO2.

If a tank that uses strong lights needs 2-3 hours to reach for example 30ppm at a given injection rate, and if CO2 concentration is stable throughout the photoperiod this means that CO2 is not limiting for the current light input (if it were, then CO2 levels would drop). If the level is stable it means that CO2 demand is in equilibrium with CO2 input. Further increasing CO2 injection will then simply increase CO2 concentration without any benefits (it only has benefits if the light input is also further increased, but such reasoning does not apply if the tank is already using the desired amount of light). Or am I missing something here?
I think Arcturus hit the money here.

The ppm would keep climbing until it reaches equilbrium with a function of offgas rate + consumption.

He also eludes to this: if your lights are maxed out, and you are happy, you don't need to go buy another light. But if you are running lights at 50% and it takes a 4 hour ramp, then turn up your lights and cut your ramp down to 3 hours. And continue this until you sandwhich it to efficiency - as comfortable as you feel. Although it sounds scary, it is not. Ya if your lights don't turn on, everything goes south fast - that's why Amano and Barr keep them on the same plug. I use smart plugs hehe.

Anyone else use a needle wheel and sump pump to inject?? 🤔😂

Unfortunately not kirsty. Different strokes for different folks would be the correct and absolute answer.
There's 2 systems at work here.

The skilled observant edge cutting guy's that push the boundaries of our knowledge. We learn lots but they gas fish with CO2. Clive admits it, suspect barr has done it in the past.

The newbies that take it nice and slow (big ramp ups, low injection rate)... pros less likely to gas fish... cons may have unhealthy plants...

Newbies also gas fish, usually when they chase higher CO2 levels.

I would never push the boundaries on CO2 because my fish are paramount, others experiment, suspect their plants are the important bit 😉

Just my musings, cary on with the discussion...

Edit: their isn't a right answer because Everyone is right ...

Think when learning everyone gases fishes - without knowing (lethargy etc). It's sad and I have a post somewhere where I am rather sad about this - can't remember but was chatting with Darrel about it about honesty in the hobby.
If fish are in distress, co2 should be turned down.

Think its really important to say that if your distribution is poor, you need to reduce your lights -- if you are against this (which I tend to just run the bad boys at 100), then you need to lean the column to compensate.
 
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JoshP12

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Well, if you are missing something. I certainly don’t know what it is.

This all makes complete sense to me but I still can’t really figure out how you get a 1ph drop on a reasonable sized tank in less than an hour. (Without dual Co2) 😩

My next theory is magic Co2, fairy dust and unicorns.

Plantbrain, come save me from my madness. 🤣

I can, however, see and would agree @JoshP12 with some of your points about the benefits of running a tank at high light. I think that’s a personal choice (possibly based on how risk averse you are!) and not something I’d necessarily recommend to a novice. It is, however, something that I would like to try in the future. Tons of light, tons of Co2, a stack of ferts and have a wee play. This would, however, first be on a tank that I didn’t mind accidentally murdering and with no fauna. After all, you learn more from the mistakes you make than you ever do from getting it right first time, and how fab would it be to achieve great results whilst pushing those boundary’s.

Right now, like a well behaved (and risk averse) newbie, I think I’ll continue to take things slow and steady. My light levels will increase some over time but I won’t be getting the lasers out anytime soon. 😊
:).
I think I’m all out of questions for now folks (Finally) or….at least until something else leaps to mind.

This has been very thought provoking and most enjoyable despite us not entirely reaching alignment on the rapid drop method 😊
Part of it in my eyes is that it actually makes each turn on the CO2 reg hit a little less hard (since my distribution is bang on, I don't worry about that -- and many standardized systems have distribution predicted by standard tank sizes and standard light and standard filters and standard outlets - proven by time) -- I used to have to do micro turns now I just do a 1/8 or 1/4 turn and the thing pearls more or less.

Well that's not true ... I have converted it to a blackwater tank with an island of emersed growth LOL -- and virtually run no co2. BUT my old posts have the old tank set ups :).
@JacksonL

Also thanks again for allowing us to unashamedly hijack your thread. Hope you’ve enjoyed the ride so far!

Yes Jackson - this is much appreciated -- been fun.
 

KirstyF

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Aha, so an 18 page thread to read through in more detail (thanks for posting link 😊) but hey, the fog is clearing.

More things may leap to mind later. 😂
 

KirstyF

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Well, that thread sure makes a good read.👍
And I’m going to apologise in advance for this following long post. Brain is still ticking!!

Firstly I’d have to say that some of my perceptions have been somewhat altered throughout this thread and the additional related research.

I figured that light was THE driver and the mechanism by which you ‘manage’ your tank as such, with ferts/Co2 needed to match it and whilst this is not entirely wrong it’s not entirely right either. Geoff shows in his thread that growth can be controlled through ferts application when both light and Co2 is delivered in abundance (in line with @JoshP12 thoughts) but it’s not simple. He has leaned out some, increased others, gone through periods of full EI (and seen a massive surge in growth) all without algae plagues, but this takes experience, quick response, and a really good understanding of how plants will react to specific dosing regimes.

Even with this knowledge, it’s still a pretty high maintenance tank and his attention to tank hygiene/waste removal was also meticulous.

Do-able yes, but not for the faint hearted.

The above with permanent full EI, would be an interesting ride for sure.

Words of wisdom given by many - if you have algae, or to prevent algae, lower your light. IMO, These are still wise words. Light may not be the problem per se, but slowing everything down gives you more room to get things wrong and/or allows you to fix the issue/deficiency before your tank crashes….and it’s easy. So long as you still have enough light, your tank won’t go into a sudden melt down. High light…..and your time to tinker is perhaps more limited. (Chances are either way, the actual issue is Co2 😂)

High light is also a bit of a misnomer. Not sure that we are really talking high light versus low light but rather highish light versus higher light. I’m guessing most Co2 injected tanks aren’t super low just maybe not full photon level.

The ramp up time issue, if I got it right, still requires you to reach equilibrium but with more than one way to skin a cat. The ‘normal’ method works….the rapid injection method works (IMO) as long as uptake and off gassing are high enough to control maximum ppm. (I’m still not convinced this gets you to 30mins ramp but hey ho) Higher light can increase uptake…I’ve got that….so the outstanding piece for me is off gassing really and specifically the mechanics of o2 and gaseous exchange.

So firstly;

Regarding rapid injection, I’m inclined to think that in most situations good distribution of 30ppm is going to cover your bases so, whilst I don’t dispute that a quicker Co2 top up may be slightly more optimal, I should imagine that the margin of difference in plant response/health is minimal. (I could be wrong) Maybe more so in a higher light tank but if you’re that close to the knife edge…..well I think I covered that! 😊

The rapid injection (including rapid off gassing) method, however, if applied well and ensuring equilibrium at 30ppm, still has the benefit of primarily only having Co2 in the tank when Co2 is needed or at least minimising Co2 outside of those times and for the fish, that is a good thing yes? My tank never fully off gasses, so not only are fish exposed to increasing Co2 for 3.5 hrs before lights on but PH only drops by 0.5 between Co2 periods. Surely condensing the time that Co2 is present, if it can be done safely, could be of benefit?

@arcturus mentioned, however, that higher surface agitation (which is the only way I would have of increasing off gassing) can reduce o2 saturation by off gassing o2 as well as Co2 and this is not a good thing.

So….Let’s assume that full o2 saturation is achieved during photo period via gaseous exchange and plant ‘respiration’. (High light may speed this but just good light should still achieve it)

Co2 is still at target 30ppm as equilibrium has been balanced at this point so Co2 level is fish safe (but good o2 levels still need to be maintained)

If we increase surface agitation, is the level of o2 that is driven off during photoperiod greater than the level of o2 that is gained via increased water surface?

I ask because, at night, when water may be o2 deficient (or in a tank with poor o2 saturation) increased water movement is advised to increase o2 levels.

Is it therefore the case that when water is o2 deficient it’s uptake of o2 from atmosphere is higher because effectively there is space for it. (Seriously dumbing this down I know but, in layman’s terms is that about right?) so night time agitation is good when o2 levels are lower (due to lack of plant produced o2) whereas during photoperiod, when the water may be fully saturated, the off gassing of o2 can be greater than the uptake of o2 and this can therefore create a net deficit?

If this is the case, if agitation is increased 24/7, would the disadvantage of o2 loss during photoperiod, outweigh the advantage of increased Co2 off gassing outside of photoperiod.

Thoughts?
 

JoshP12

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@KirstyF - what a nice read through your thoughts.

On the O2 saturation piece, I'd argue that to have high off-gas, you need high light. It's almost like offgas, send the water through, saturate with O2 like crazy, off gas, load up the co2 like crazy, load up the O2 like crazy (max light you can with - call that high light) from photosynthesis -- rinse and repeat.

So although you bring O2 back to, you also super saturate it all over. And then with everything in place, you load up CO2, then the swoop comes, the plants drink all the CO2, they make LOADS of oxygen, then maybe you can't offgas all the oxygen (due to turnover) but you have no CO2 (since they drank it), so it fills up, then swoop once more - plants suck it all up and make even more oxygen.

Not sure the degas will hurt O2 level if paired with max light.

For the record I run 4x AI Primes at 100% hehe.

Going to think on the rest of the post. Maybe the above will help us think more?

And actually as I write this, I think this makes an argument towards "max light <-- my new word" due to O2 saturation? To it being a worthy benefit to sandwhich down that ramp.

Edit:

@KirstyF On this: whilst I don’t dispute that a quicker Co2 top up may be slightly more optimal, I should imagine that the margin of difference in plant response/health is minimal.

Probably would be seen as less stunting - could be the difference between 1/5 stems to 1/10. ?

@KirstyF On this: Is it therefore the case that when water is o2 deficient it’s uptake of o2 from atmosphere is higher because effectively there is space for it.

Yes. It's Fick's law. You didn't simplify it at all. It's the correct intuition.
 
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arcturus

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(...)
Is it therefore the case that when water is o2 deficient it’s uptake of o2 from atmosphere is higher because effectively there is space for it. (Seriously dumbing this down I know but, in layman’s terms is that about right?) so night time agitation is good when o2 levels are lower (due to lack of plant produced o2) whereas during photoperiod, when the water may be fully saturated, the off gassing of o2 can be greater than the uptake of o2 and this can therefore create a net deficit?


If this is the case, if agitation is increased 24/7, would the disadvantage of o2 loss during photoperiod, outweigh the advantage of increased Co2 off gassing outside of photoperiod.
 

JoshP12

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@arcturus curated those two nice quotes together.

This is serious proportional reasoning. And we are trying to guess without the mathematics.

On the second piece: @KirstyF If this is the case, if agitation is increased 24/7, would the disadvantage of o2 loss during photoperiod, outweigh the advantage of increased Co2 off gassing outside of photoperiod.

It's a tough one -- I mean who is being affected negatively by having gas in the water? Do fish care between 20ppm or 15 ppm or 30 ppm or exposure to 20 for 20 hours vs 30 for 6? These are not easy questions.

I think maybe the intuition here may "reduce" the extent that the O2 loss happens?
On the O2 saturation piece, I'd argue that to have high off-gas, you need high light. It's almost like offgas, send the water through, saturate with O2 like crazy, off gas, load up the co2 like crazy, load up the O2 like crazy (max light you can with - call that high light) from photosynthesis -- rinse and repeat.

So although you bring O2 back to, you also super saturate it all over. And then with everything in place, you load up CO2, then the swoop comes, the plants drink all the CO2, they make LOADS of oxygen, then maybe you can't offgas all the oxygen (due to turnover) but you have no CO2 (since they drank it), so it fills up, then swoop once more - plants suck it all up and make even more oxygen.

Not sure the degas will hurt O2 level if paired with max light.

I did use a Dissolved Oxygen probe (after I fixed it) and that oxygen goes up whether we like it or not during the photoperiod - with constant off-gassing. I mean, if I remember (I'd have to dig through my photos to find the shots), it goes like this:
1642037303423.png


The max saturation point was almost perfectly timed with pearling (I mean don't attack my proportions here) -- but it pearled and around the exact same time we had max saturation and then when the super pearling happened all through the tank, a micro blip to a new point. But I mean error too. Still the oxygen went up, it did not off gas as predicted via the proposed model - so the "swoop" suggestion in conjunction with Fick's law that you demonstrated (simultaneous off gas from agitation and top up from injector) -- although loads of proportional stuff happening here all at once -- it "must" apply?
 
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arcturus

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Surface agitation (regardless of the method) promotes gas exchange between the water and atmosphere. With ideal gas exchange, the water will saturate and reach a point of equilibrium with the atmospheric gases. At sea level (1 atm) and 25C, water becomes saturated with ~8 mg/L of dissolved O2 and with ~2 mg/L of dissolved CO2. These values decrease when temperature increases and also depend on pressure (CO2 dissolution is actually way more complicated due to chemical processes such as those involving carbonic acid and carbonate ions).

During the night, the O2 level in a planted tank will decrease due to plant respiration. To offset this loss we can increase surface agitation to increase the dissolution of atmospheric O2 in the water. With CO2 the process is similar and the CO2 levels will converge (but may not reach) the equilibrium point (~2 mg/L).

During the day, the plants are consuming CO2 and producing O2 as a byproduct of photosynthesis. With enough plant mass and photosynthesis, the amount of produced O2 will increase above atmospheric equilibrium (basically, the plants are "injecting" O2 into the water). If we now increase gaseous exchange then we reduce O2 as well as CO2.

The total amount of O2 and CO2 in the water will be a combination of dissolved and undissolved gas. For example, if we have a tank with x ppm CO2 and with CO2 mist/bubbles in the water, then the total amount of CO2 in the water will be higher than x ppm but a part of it is not dissolved. Same applies to O2. The O2 bubbles resulting from plant "pearling" are undissolved O2. This means that we can actually "over-saturate" the water with O2 and CO2. When we increase the surface agitation we are pushing out of the tank both dissolved and undissolved gases. The dissolution rate of CO2 in water is ~200x higher than O2 and undissolved gases are off gassed faster than dissolved gases. So, during photosynthesis the undissolved O2 will take a direct hit with increased gaseous exchange.

The (oversimplified) dynamics of these processes are something like this:
1642084289307.png


The goal of agitation during the photoperiod is to balance CO2 input with CO2 output <to reach CO2 stability>. The higher the gas exchange, the higher the O2 loss (of course, we would need controlled experiments to measure the dynamics). This is curve "A" that Dennis Wong shows in the diagram below.
1642079435310.png


The goal of agitation outside the photoperiod is to increase O2 levels to offset plant respiration; the decrease of CO2 levels is a side effect, not the goal.

IMO, during the photoperiod, agitation should be the minimum necessary to reach equilibrium. Above that minimum agitation we are wasting injected CO2 while unnecessarily reducing the O2 levels. If we try to shorten the ramp up period then we need more CO2 injection and then need more off gassing to keep the CO2 at "optimal level", but this will reduce O2. If we continue increasing agitation we might reach a point where all extra O2 from the plants is off gassed (we would need controlled experiments to verify if this is possible). So, IMO, once we reach CO2 stability at a given light/PAR input it makes no sense to further increase CO2 injection or agitation to try shortening the ramp up period.
 

JoshP12

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Those diagrams are beauties.
If we try to shorten the ramp up period then we need more CO2 injection and then need more off gassing to keep the CO2 at "optimal level", but this will reduce O2.
However, the benefit of having faster refresh on CO2 - only if we pair this with increased light to drive demand back to the point of which CO2 is no longer in excess.
If we continue increasing agitation we might reach a point where all extra O2 from the plants is off gassed (we would need controlled experiments to verify if this is possible). So, IMO, once we reach CO2 stability at a given light/PAR input it makes no sense to further increase CO2 injection or agitation to try shortening the ramp up period.
100% yes - it is not smart, BUT if we pair it with increased light, we increase the rate of O2 evolution (by driving photosynthesis further).

Agree it is not smart to increase agitation just to increase CO2 injection rate if your tank is already at stability. However, if there is a benefit to a faster refresh on CO2, and we pair this with an increase of light, we can match the O2 saturation via increased photosynthesis.

At the forefront it seems that the only reason we would ever consider this is if we want maximum light to support life. If we see no benefit in higher lights, then this approach seems rediculous. But if we see the benefit of light, then it becomes a valid question.

Is it worth it?

Can the increase of light (and photosynthesis) compensate for the O2 loss while gaining the added stability- from a system perspective - (due to faster top up rate) from higher injection rate and the decreased exposure to CO2 during lights off (maybe not the exposure to livestock but because starting it with lights on allows for faster injection rates to stabilize localized CO2 levels in the tank). CO2 has the highest likelihood of being the issue - it doesn't matter how you skin it and play with it - half the plant is carbon so whether its due to nutrient demand pushing CO2 etc, it's going to be CO2. So stable, localized CO2 levels are always a benefit.

It is possible that the tank can handle higher levels than 30, if in one swoop, it is being depleted and turned into O2, balancing the livestock needs.

As we go through this, it becomes remarkably clear why EI + High Light + High gas exchange + high turnover leads to massive amounts of success. You can also see why Tom Barr - with his set up (wet/dry, high light, reactor, ADA soil always fresh, consistent multiple water changes that bring the water column back to the datum)- has no issues with nutrients and CO2 (despite the nutrients driving CO2 demand through the column). And why in conjunction, someone with not so intense of a system may struggle under an EI dosing regime. He obtains plant forms that people need nutrient restriction for - they simply don't have the tech to support them.
 
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KirstyF

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Wow guys. This is fabulous. I’m going to re-read these posts 3 times when I get home but already so much easier to get my head around than the scientific papers I was Googling! 😊
 

KirstyF

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Thank you guys for these really clear explanations, I now have a much better understanding of the mechanics of gaseous exchange.

For me ultimately this means I need make no changes to my tank currently but leaves me better able to understand the interactions between and impact of the various elements that we control.

The exploration of the workings of a ‘maxed tank’ whilst not being appropriate for either the goals of my current set-up or, IMO, my current experience level, has still been both an enlightening and a useful process.

It’s certainly given me lots to think about…..and from little acorns do mighty oaks grow! 😊
 

KirstyF

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Thank you guys for these really clear explanations, I now have a much better understanding of the mechanics of gaseous exchange.

For me ultimately this means I need make no changes to my tank currently but leaves me better able to understand the interactions between and impact of the various elements that we control.

The exploration of the workings of a ‘maxed tank’ whilst not being appropriate for either the goals of my current set-up or, IMO, my current experience level, has still been both an enlightening and a useful process.

It’s certainly given me lots to think about…..and from little acorns do mighty oaks grow! 😊
 

dw1305

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Hi all,
Surface agitation (regardless of the method) promotes gas exchange between the water and atmosphere. With ideal gas exchange, the water will saturate and reach a point of equilibrium with the atmospheric gases. At sea level (1 atm) and 25C, water becomes saturated with ~8 mg/L of dissolved O2 and with ~2 mg/L of dissolved CO2. These values decrease when temperature increases and also depend on pressure (CO2 dissolution is actually way more complicated due to chemical processes such as those involving carbonic acid and carbonate ions).
During the night, the O2 level in a planted tank will decrease due to plant respiration. To offset this loss we can increase surface agitation to increase the dissolution of atmospheric O2 in the water. With CO2 the process is similar and the CO2 levels will converge (but may not reach) the equilibrium point (~2 mg/L).
During the day, the plants are consuming CO2 and producing O2 as a byproduct of photosynthesis. With enough plant mass and photosynthesis, the amount of produced O2 will increase above atmospheric equilibrium (basically, the plants are "injecting" O2 into the water). If we now increase gaseous exchange then we reduce O2 as well as CO2.
Same for me, I also like surface agitation (a <"large gas exchange area">), I really don't see any downsides to this for the low-tech aquarist.

Along with the the abiotic factors you have to <"take plant structure"> into account as well. Plants are <"full of spaces where gas can collect">. The net effect of this is that the internal tissue will be saturated with oxygen when light is above the LCP. At night this stored oxygen will be used for respiration and CO2 will accumulate and be available for photosynthesis once PAR is high enough. If you get pearling? You have a visible indication that the air spaces are saturated with oxygen.

aerenchyma2-jpg.161594

Aerenchyma : by User:Bb143143 - Self-photographed, CC BY-SA 3.0, File:Aerenchyma2.JPG - Wikimedia Commons

cheers Darrel
 

Wookii

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Hi all,



Same for me, I also like surface agitation (a <"large gas exchange area">), I really don't see any downsides to this for the low-tech aquarist.

Along with the the abiotic factors you have to <"take plant structure"> into account as well. Plants are <"full of spaces where gas can collect">. The net effect of this is that the internal tissue will be saturated with oxygen when light is above the LCP. At night this stored oxygen will be used for respiration and CO2 will accumulate and be available for photosynthesis once PAR is high enough. If you get pearling? You have a visible indication that the air spaces are saturated with oxygen.

aerenchyma2-jpg.161594

Aerenchyma : by User:Bb143143 - Self-photographed, CC BY-SA 3.0, File:Aerenchyma2.JPG - Wikimedia Commons

cheers Darrel

In that case, do you think plants would need to draw any additional oxygen from the water column?
 

arcturus

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In that case, do you think plants would need to draw any additional oxygen from the water column?
Along with the the abiotic factors you have to <"take plant structure"> into account as well. Plants are <"full of spaces where gas can collect">. The net effect of this is that the internal tissue will be saturated with oxygen when light is above the LCP. At night this stored oxygen will be used for respiration and CO2 will accumulate and be available for photosynthesis once PAR is high enough. If you get pearling? You have a visible indication that the air spaces are saturated with oxygen.
Is there any experimentation measuring the actual oxygen intake from plants during respiration in a limited enclosed space, such as a planted tank ? I understand that, conceptually, respiration can be an issue. But is it really an issue in practice?
 

dw1305

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Hi all,
In that case, do you think plants would need to draw any additional oxygen from the water column?
They probably still do, it is going to depend on all sorts of factors, but oxygen related fish death in planted tanks <"tends to occur at night">, suggesting that it is the extra oxygen demand, from plant respiration, that has tipped the the tank over the edge.

Sometimes, when you tell the, recently bereaved, owner that:
  • All that had been keeping their fish alive (before their recent demise) was the <"plant based life support system"> and
  • that oxygen related deaths are really uncommon in planted tanks
It doesn't <"go down very well">, but that maybe because <"I am particularly tactless">.
Is there any experimentation measuring the actual oxygen intake from plants during respiration in a limited enclosed space, such as a planted tank ? I understand that, conceptually, respiration can be an issue. But is it really an issue in practice?
I'd guess not. I think @Geoffrey Rea ran a Dissolved Oxygen (DO) meter over twenty-four hours in a high tech tank, but I can't find the thread*.

*edit <"Found it">

cheers Darrel
 
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