When exactly to add aeration in low tech aquarium

[teambedell]

So I’ve been doing a lot of research on when to aerate a planted aquarium. Most everything I’m finding is to aerate at night, about an hour after the lights are turned off, and the plants are breathing oxygen. Then turn off the aeration during the day when the lights come on again. My aquarium is low tech.

My question is: is this daytime/nighttime specific, or lights on/off specific?

I understand the “when the lights are on part”; but, I only run my lights 7 hours a day (4:00 pm to 11:00 pm, when I’m most available to enjoy the view). What about the daytime hours when the lights are off, and it’s quite dim in the tank from only ambient light? Should I be aerating during this time, or at least some of this time? The tank is in a room with a large window, but not in direct light of any kind. I guess I don’t know what minimum amount of light produces any significant photosynthesis, or how much supplemental O2 is needed in a dim tank without lighting during the day.

Thanks!

Edited August 28 by teambedell

[Tony s]

On 8/28/2024 at 12:54 PM, teambedell said:

Should I be aerating during this time, or at least some of this time

I run 14 tanks. I never aerate for the plants, only for the fish. Yes, there is a process in plants that occurs during the night called dark respiration. when photosynthesis shuts down, and standard respiration and growth occur. When they stop absorbing co2 and start using regular oxygen. But I real doubt the need to oxygenate the water for that. Now fish, on the other hand, always appreciate the extra oxygen

[teambedell]

On 8/28/2024 at 12:15 PM, Tony s said:

I run 14 tanks. I never aerate for the plants, only for the fish. Yes, there is a process in plants that occurs during the night called dark respiration. when photosynthesis shuts down, and standard respiration and growth occur. When they stop absorbing co2 and start using regular oxygen. But I real doubt the need to oxygenate the water for that. Now fish, on the other hand, always appreciate the extra oxygen

Well, I guess I didn’t specify that it’s for the fish as well. So, when the fish and plants are both consuming O2, I will aerate so there’s plenty to go around. When the plants are producing O2, I will cease aeration, because I don’t want to dissipate the CO2 for the plants (especially where I’m not supplementing CO2). So I’m just wondering what the plants are doing in a dim tank during the daytime, as in my picture. Are they consuming O2, or still CO2? Knowing this will answer when I want to schedule my air stone/pump to turn off on the timer.

[Tony s]

On 8/28/2024 at 1:48 PM, teambedell said:

Are they consuming O2, or still CO2

Nice setup. I like the flex. We have 2 for guppies.  Would have never thought of putting the plant there. but it works.

I don't believe dark respiration happens at all until it's quite dark. sunset dark or darker. low light plants are still going to photosynthesize in ambient light. But really, I'd just leave it going. It's not going to do any harm. And I doubt cycling like that is actually going to help much either. As for carbon dioxide, that is going to be a limiting factor, no matter what you do. 

[teambedell]

On 8/28/2024 at 1:02 PM, Tony s said:

Nice setup. I like the flex. We have 2 for guppies.  Would have never thought of putting the plant there. but it works.

I don't believe dark respiration happens at all until it's quite dark. sunset dark or darker. low light plants are still going to photosynthesize in ambient light. But really, I'd just leave it going. It's not going to do any harm. And I doubt cycling like that is actually going to help much either. As for carbon dioxide, that is going to be a limiting factor, no matter what you do. 

Thanks! I actually saw a YouTuber who stuck a pothos in the feeding hole. Upon further research, I saw that there are 3-D accessories printed on Etsy to hold plants, but that seems unnecessary. 
 

So you don’t think aeration during the day will reduce the CO2 that much? I of course still have the back filter going and creating aeration. Chambers one and two are full of lava rock and other assorted biomedia, and three layers of filter floss. Chamber 3 has a pouch of Purigen next to the pump. I’m sure I have a large community of beneficial bacteria for the tank size, so O2 is certainly a good thing. 

[Tony s]

On 8/28/2024 at 3:29 PM, teambedell said:

So you don’t think aeration during the day will reduce the CO2 that much?

It might a bit, but I'm not sure it's enough to make a difference.

On One of our Flex's it's full of kuhli loaches. I gave up trying to keep them out 🤣

[JoeQ]

In a low tech I would keep the bubbler on 24/7, reason being is the water will absorb a small amount of co2 as the bubbles rise to the surface. It will also help with surface agitation, again bringing in co2.

In a low tech aquarium your growth limiting factor will be co2. You must optimize surface/gas exchange.

 

[teambedell]

On 8/28/2024 at 2:32 PM, JoeQ said:

In a low tech I would keep the bubbler on 24/7, reason being is the water will absorb a small amount of co2 as the bubbles rise to the surface. It will also help with surface agitation, again bringing in co2.

In a low tech aquarium your growth limiting factor will be co2. You must optimize surface/gas exchange.

 

Thanks. Although all the research online indicates that aerating, with CO2 supplementation, would dissipate CO2, not increase it. Wouldn’t that be even more the case with only naturally occurring CO2?

I do agree with Tony that the dim light is enough for photosynthesis with low/medium light plants. That’s what I was most concerned about, not aerating when plants are consuming CO2. As far as O2 levels. My fish are very active all day, so they’re breathing just fine. At night, I have no way of knowing that, so more O2 for everything: plants, fish, and bio filter seems like good insurance.

[JoeQ]

There's also something to be said about the benefits of highly oxygenated water not only to your inhabitants but also for your benifical bacteria

Edited August 28 by JoeQ

[teambedell]

On 8/28/2024 at 2:32 PM, Tony s said:

It might a bit, but I'm not sure it's enough to make a difference.

On One of our Flex's it's full of kuhli loaches. I gave up trying to keep them out 🤣

I’ve got a Yo-yo Loach in mine. He may end up outgrowing the tank, but the local aquarium store owner is a friend and will swap him out for a smaller one if the time comes. Sometimes they don’t end up getting that big, so fingers crossed 🤞

[JoeQ]

On 8/28/2024 at 3:51 PM, teambedell said:

Thanks. Although all the research online indicates that aerating, with CO2 supplementation, would dissipate CO2, not increase it. Wouldn’t that be even more the case with only naturally occurring CO2?

I do agree with Tony that the dim light is enough for photosynthesis with low/medium light plants. That’s what I was most concerned about, not aerating when plants are consuming CO2. As far as O2 levels. My fish are very active all day, so they’re breathing just fine. At night, I have no way of knowing that, so more O2 for everything: plants, fish, and bio filter seems like good insurance.

If you are injecting with co2 I do not know the results of running aeration along side. I have not run those comparisons. I do know from experience (not a Google search) in a non injected tank (low tech) running aeration 24/7 produces far better results than no aeration when lights are on

[teambedell]

On 8/28/2024 at 2:53 PM, JoeQ said:

There's also something to be said about the benefits of highly oxygenated water not only to your inhabitants but also for your benifical bacteria

I don’t disagree with you. I’m just convinced I’ve got plenty of O2 during the day, just based on the activity of my fish. If the beneficial bacteria was suffering, the fish would indicate that as well IMO. Everyone is enjoying O2 at night, so I pour it on. I just wanted to avoid limiting CO2 during the period the plants benefit from it.

[Tony s]

Okay. I'm a bit thick. @teambedell @JoeQ Took me a minute. Running an airstone will increase O2 and co2. You're pulling in air. Not oxygen. It will have the same composition of the stuff we're currently breathing. Both are more than concentrated than what water can carry. My apologies for whomever got you started down that tangent. keep it running. You're good

[JoeQ]

On 8/28/2024 at 4:04 PM, teambedell said:

I don’t disagree with you. I’m just convinced I’ve got plenty of O2 during the day, just based on the activity of my fish. If the beneficial bacteria was suffering, the fish would indicate that as well IMO. Everyone is enjoying O2 at night, so I pour it on. I just wanted to avoid limiting CO2 during the period the plants benefit from it.

Plants pearling should be your metric for o2 levels, not 'my fish seem fine'.

[teambedell]

On 8/28/2024 at 3:01 PM, JoeQ said:

If you are injecting with co2 I do not know the results of running aeration along side. I have not run those comparisons. I do know from experience (not a Google search) in a non injected tank (low tech) running aeration 24/7 produces far better results than no aeration when lights are on

I’ll try doing air 24/7 and see. When I make a change, I wait 2 weeks to note the results. I just started this experiment. I’ll make that change after. I use google to search the topics, but there are go-to people on YouTube I trust, with tons of experience. 

On 8/28/2024 at 3:07 PM, JoeQ said:

Plants pearling should be your metric for o2 levels, not 'my fish seem fine'.

Read you loud and clear. Thanks.

[JoeQ]

On 8/28/2024 at 4:07 PM, Tony s said:

My apologies for whomever got you started down that tangent.

I think somehow the topic got changed from 'At what time should I start aeration on a low tech tank' By me explaining why it was important  to aerate 24/7 (my short answer would have been all the time) instead I chose to stress the importance of optimizing gas exchange. Which I guess muddled the topic

Edited August 28 by JoeQ

[Tony s]

On 8/28/2024 at 4:25 PM, JoeQ said:

instead I chose to stress the importance of optimizing gas exchange

Yeah, I got that. I just question the person that said only aerate at night. Unless you're pulling from a straight O2 cylinder, that makes no sense at all. Just by running a stone you're increasing gas exchange. Of all atmospheric gasses. I think a lot of people, me included, way over think this hobby sometimes 

[JoeQ]

On 8/28/2024 at 4:31 PM, Tony s said:

Yeah, I got that. I just question the person that said only aerate at night. Unless you're pulling from a straight O2 cylinder, that makes no sense at all. Just by running a stone you're increasing gas exchange. Of all atmospheric gasses. I think a lot of people, me included, way over think this hobby sometimes 

I blame the loss of non verbal communication when interacting thru text....   As for the over thinking part, I would 'think' 🤣 that is what keeps sooo many of us addicted to the hobby!

[teambedell]

On 8/28/2024 at 3:31 PM, Tony s said:

Yeah, I got that. I just question the person that said only aerate at night. Unless you're pulling from a straight O2 cylinder, that makes no sense at all. Just by running a stone you're increasing gas exchange. Of all atmospheric gasses. I think a lot of people, me included, way over think this hobby sometimes 

Even if you were drawing from an O2 cylinder, it wouldn’t oxygenate your water anymore than what occurs through surface agitation; at least not significantly. 

[Woowala]

I would just track the pH throughout a couple days to see how much photosynthesis is occurring during those dim periods.  I expect the difference is little though, maybe undetectable, and would probably just aerate 24/7.   

[teambedell]

Keep in mind I wasn’t aerating at all up to this point; so, even aerating only at night is significant improvement 😆

[yancylow]

On 8/28/2024 at 4:16 PM, teambedell said:

Keep in mind I wasn’t aerating at all up to this point; so, even aerating only at night is significant improvement 😆

Imagine the benefits when you'll start aerating during the day too, woah!!

[Pepere]

On 8/28/2024 at 1:48 PM, teambedell said:

So, when the fish and plants are both consuming O2, I will aerate so there’s plenty to go around. When the plants are producing O2, I will cease aeration, because I don’t want to dissipate the CO2 for the plants (especially where I’m not supplementing CO2)

In a non injected tank, I dont think it will amount to much difference…

 

Running an air pump at night will increase gas exchange increasing oxygen but also reducing CO2.  Normally with lights off the plants give up co2 to the water, but you will gas that off.  Normally when light comes on the plants take up available co2 pretty quick and then the tank doesnt have much anymore…. Abd if the plants cant take up co2, phtosynthesis slows and o2 output from the plants decrease as well…

I would keep one on continually…

[teambedell]

On 8/28/2024 at 8:10 PM, Pepere said:

In a non injected tank, I dont think it will amount to much difference…

 

Running an air pump at night will increase gas exchange increasing oxygen but also reducing CO2.  Normally with lights off the plants give up co2 to the water, but you will gas that off.  Normally when light comes on the plants take up available co2 pretty quick and then the tank doesnt have much anymore…. Abd if the plants cant take up co2, phtosynthesis slows and o2 output from the plants decrease as well…

I would keep one on continually…

That seems to be the consensus. That’s why I joined this forum. No need getting over technical in a low tech tank 😁 Air on 24/7 it is! 👍🏻

[teambedell]

So to confirm, besides not running an air stone when you ARE injecting CO2 due to off gassing it too quickly, the fish are getting all the O2 they need from just the plants and filter during the day from increased photosynthesis. And in a low tech aquarium, the plants aren’t giving off as much O2, to where supplementing an air stone is a good idea all the time. Correct?

Edited August 29 by teambedell