# Aeration in planted tank



## Qwertus

Is it better to have those bubblers or not in a planted tank? At the moment, I have it on only when the lights are off.


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## aquabillpers

All that the bubblers do is to provide some surface motion. They do not in themselves add any oxygen to the water.

They might cause scarce CO2 to go from the tank to the atmosphere.

I'd suggest not using them.

Bill


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## Diana K

Running a bubbler at night is often done to reduce the CO2 while the plants are not using it, but are actually producing it.


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## jazzlvr123

co2 exponentially reduces the amount of O2 that can be dissolved an a tank at any given time. diffusing O2 at night degases Co2 in the water making more O2 available to fish and subsequently making them happier and healthier in the long run plants also benefit from O2 at night time. Overall O2 at night is a win win situation I've been doing it for a long time.


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## essabee

In planted tanks which are not being enriched with CO2 supply, the aeration during day and night is a win win situation. At night it prevents the over utilisation of (therefore possible depletion in) O2 in densely planted/over stocked tanks; and during the day keeps CO2 levels from going down under the pressure of photosynthesis, by keeping the diffusion from the atmosphere at a higher level.

In tanks being enriched with CO2, aeration during the day will increase the escape of CO2 as nature will tend to keep the gas in the tank at the same proportional level as CO2 concentration in the atmosphere.


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## aquabillpers

Diana K said:


> Running a bubbler at night is often done to reduce the CO2 while the plants are not using it, but are actually producing it.


It is hard to imagine a scenario in which a NPT developed excessive CO2. CO2 is the limiting factor in a NPT (after light) and the problem is in conserving it, not getting rid of excessive build-ups.

High tech tanks with CO2 injection typically run at 20 to 40 ppm. I doubt that a NPT ever gets much above 5 or 6 ppm. (Those with CO2 testing devices, please help. I could be wrong.)

Now, it is possible to have too many fish in a tank, planted or bare, and aeration might be required to keep them alive. That can be done in a NPT, too, but one should be aware that dong it will have a negative effect on plant growth.

Bill


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## dwalstad

aquabillpers said:


> It is hard to imagine a scenario in which a NPT developed excessive CO2. CO2 is the limiting factor in a NPT (after light) and the problem is in conserving it, not getting rid of excessive build-ups.
> 
> High tech tanks with CO2 injection typically run at 20 to 40 ppm. I doubt that a NPT ever gets much above 5 or 6 ppm. (Those with CO2 testing devices, please help. I could be wrong.)
> 
> Now, it is possible to have too many fish in a tank, planted or bare, and aeration might be required to keep them alive. That can be done in a NPT, too, but one should be aware that dong it will have a negative effect on plant growth.
> 
> Bill


Thank you, Bill. Well said.

The only time I would ever use aeration is if the fish are struggling for oxygen. This can happen in some new NPTs (first 8 weeks) when the new soil can deplete water oxygen. The soil bacteria are decomposing the fresh organic matter so fast that they could conceivably consume all oxygen and fill the water with high levels of CO2. This is unhealthy for fish, especially in the early morning before oxygen generation (via plant photosynthesis) kicks in.

Thus, when you set up your NPTs, look out for this problem during the first 8 weeks. You may or may not need aeration. This will depend on how deep the tank is, water surface area, amount/type of soil, etc. Let fish behavior guide you.

A case could be made for doing some light aeration at night in new tanks with fresh soil. This is the time when your fish will need it the most.

In my tanks, the water gets enough aeration just via water movement fromt the filters. I don't use airstones unless I see a fish problem or don't have a filter. Bubbling via air-stones will remove CO2 from the water, and CO2 is the limiting nutrient for plant growth in NPTs.


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## Alex123

I don't have any filter or aeration in my 10 and 20 gallon for over a month. I have yet to see any problem with the fishes. I have about 20 inches of bio load containing small community fishes and countless snails in the 20 and about 10 inches of bio load in my 10 g not including tail part. So far I have yet to see any problem. Maybe I might be concerned if the bio load goes up more but so far so good.


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## dwalstad

Every ecosystem is different. (That's what makes them interesting.) Sometimes you may need to add aeration, or as in your case, you're fine without it. 

Thanks for writing.


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## essabee

dwalstad said:


> Every ecosystem is different. (That's what makes them interesting.) Sometimes you may need to add aeration, or as in your case, you're fine without it.
> 
> Thanks for writing.


These words are so true, and the reason for keeping an open mind and remembering what to do in given state of affairs.


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## Alex123

Just when I said, I am doing fine my 20 gallon for the past week turned cloudy. I don't know if it's not running filter/pump or because I removed all the hornworts. (have amazon sword, westeria, anacharis, java fern) I haven't used filter for over a month and removed the hornworts a couple weeks ago. I have only 1.5 to 1.7 wpg on my tank and had some issues with algae on my plants and I did some cleaning(my first water change since setting the tank up 5 gallons change(one to two weeks ago) and removed the algae covered hornworts. I have since added a 10 gallon power filter and added the hornworts back. My tank water is very grayish/whitish color and I can't see the fish very well if more than a foot away. The plants seems to be doing much better than before I took out the hornworts and not a lot of algae. So it really perplexing me that I have this clouding issue. Bacterial bloom is what I have read online. I have 1 inch of topsoil covered by half inch of substrate(ran out of substrate). It's been running for over 3 months. I changed water 3 days in a row at about 2 gallons per change the last few days. That didn't do anything. It probably made it a little worse. The fishes look fine and the plants are looking better than ever. Any suggestions?


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## Muirner

Can i ask how come your not running a filter on your tank? There could be dozens of reasons in my opinion to why this is happening but first i'd like to ask why your nor running a filter or at least a pump?

Your hornwort probably grew like a weed when it was in the tank, thus sucking up excess harmful chemicals (Nitrate, Nitrite, Ammonia). When you removed this, a lot of "filtering power" (term used very lightly) was removed with the plant. Plants them selves are filters in a small sence. 

I just want to point out that a filter establishes benificial bacteria in the aquarium helping to deal with any chemical spikes in the aquarium. I think without a filter your running the risk of the soil going anarobic (right term??), a huge nutrient spike, the inability to cope with it. And thus the potential recycling of your tank.

So i ask again. Why do you not run a filter or a pump on a tank expecially when your removing a lot of plant mass?


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## ghengis

essabee said:


> In planted tanks which are not being enriched with CO2 supply, the aeration during day and night is a win win situation. *1. At night it prevents the over utilisation of (therefore possible depletion in) O2 in densely planted/over stocked tanks*; *2. and during the day keeps CO2 levels from going down under the pressure of photosynthesis, by keeping the diffusion from the atmosphere at a higher level.*
> *3. In tanks being enriched with CO2, aeration during the day will increase the escape of CO2 as nature will tend to keep the gas in the tank at the same proportional level as CO2 concentration in the atmosphere*.


Sorry, but you're going to have to explain this a little further... 
1. How does an aerator (bubbler) _prevent_ utilisation of O2 in a planted/stocked tank? A bubbler _adds_ oxygen to a tank (at least thru agitating the surface), I don't see how adding O2 can prevent O2 being utilised...

2. And then during the day prevents CO2 levels from _dropping_??? Surely the "diffusion from the atmosphere" is exactly what _reduces_ CO2 levels, by way of gaseous exchange with O2 at the water surface (as mentioned above)...?

3. Wouldn't having CO2 gassing off (escaping) during the day makes the whole idea of putting it (CO2) in the tank in the first place pointless? I thought the whole reason for _not_ having a bubbler was so the plants could absorb as much CO2 as possible and produce oxygen (by way of photosynthesis) for the fishies to breathe? As for keeping CO2 levels in the tank in proportion, isn't that why we have needle valves, bubble counters and drop checkers...?

Sorry, I don't mean to be terse, but are you sure you haven't got all this back-to-front?


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## Alex123

Muirner after coming from home the water looks really cloudy and greenish looking too. I think its green water. I have never had it but I guess it starts off grayish white and turn green? Now I can't see more than 6 inches. I am glad it's green water since now I know that the aquarium is setup correctly(yeah irony) and it's only(lol) algae problem. I don't have filter because I heard some people in this forum having luck with small aquarium with no filters of any kind. My hornworts kept the water from going green it seems. The power filter I put in couple days ago made the water go even more green.


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## essabee

> Sorry, but you're going to have to explain this a little further...
> 1. How does an aerator (bubbler) prevent utilisation of O2 in a planted/stocked tank? A bubbler adds oxygen to a tank (at least thru agitating the surface), I don't see how adding O2 can prevent O2 being utilised... 'over utilisation' was the word, over utilisation of a limited supply; aeration constantly adds to the supply preventing over utilisation
> 
> 2. And then during the day prevents CO2 levels from dropping??? Surely the "diffusion from the atmosphere" is exactly what reduces CO2 levels, by way of gaseous exchange with O2 at the water surface (as mentioned above)...?diffusion from atmosphere does not reduce or increase CO2 levels if the level is at the ratio as ruled by the CO2 content in the atmosphere. In CO2 enriched tanks the content of CO2 in tank water is higher than sustainable by normal atmospheric condition -- here diffusion will be acting to reduce CO2 content in the tank; In non-enriched CO2 tanks the CO2 level is what is naturally caused by CO2 content in the atmosphere, photosynthesis causes reduction of CO2 content from this natural level, here diffusion will be acting to increase the CO2 content in the tank. The aerator does not do anything other than increase the rate of diffusion by increasing the surface area for diffusion
> 
> 3. Wouldn't having CO2 gassing off (escaping) during the day makes the whole idea of putting it (CO2) in the tank in the first place pointless? I thought the whole reason for not having a bubbler was so the plants could absorb as much CO2 as possible and produce oxygen (by way of photosynthesis) for the fishies to breathe? As for keeping CO2 levels in the tank in proportion, isn't that why we have needle valves, bubble counters and drop checkers...? Your use of the word 'proportion' is to mean high, while I have used it to mean in the proportion as in the atmosphere. I think this is where you missed my point.
> Sorry, I don't mean to be terse, but are you sure you haven't got all this back-to-front? No, its quite simple, read it again.


I hope the answers given in blue satisfies you.

Diffusion of gases will take place at all times and all along the surface of division. If the proportion of gases interse is the same on either side of the surface of the division then a dynamic equilibrium will be maintained. If the proportion of gases interse is *not* the same on either side of the surface of the division then the tendency will be to equalize the differences. The rate of diffusion is directly related to surface area of division of the gases.


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## ghengis

Hmmmm...sorry, I'm still confused. Probably due to everything that I have read to date on CO2 enrichment warns against excess surface agitation, due to it's causing "gassing off", and therefore wastage, of the CO2.

For example, there is a divide among the hobby over the use of HOB filters on CO2 enriched systems. It is widely suggested (and to my mind, with perfect logic) that the disruption where the filter outflow breaks the surface causes CO2 loss. I have therefore just surmised that one really wants to keep as much of the gas _inside_ the tank as possible.

Your statement about gasses (O2, CO2 or otherwise) finding a natural equilibrium on both sides of a permeable membrane seems to ring true. I can get a handle on that, and you are likey correct. The question would then beg, though, why even inject CO2 into a tank when all that will happen is that it'll continue to find that point of equilibrium? And that regardless of how much CO2 one were to inject, it'd just gas off and never end up in any greater concentration than atmospheric? Why not just be happy with atmospheric CO2 content diffusing it's way beyond the surface of the water to grow the plants?

You've got me thinking, now!!


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## helenf

Most people running "el natural" planted tanks are not using artificial CO2 enrichment. The only sources of CO2 are therefore

- respiration of plants and animals
- decay of carbon stuff in the tank (I think this produces a little CO2, please correct me if I'm wrong)
- CO2 from the air dissolving into the water.

Since the first two only happen on a small scale, it is the third that provides most of the carbon to the plants in these tanks. Since the plants are capable of using CO2 faster than the rate at which it dissolves into the water, it is normal for the CO2 in the water to be lower, during the day, than the usual equilibrium point with the air. In this situation, any additional aeration will increase the CO2 and help the plants.

It is important to remember that "aeration" doesn't only change oxygen levels. It will change the levels of all of the gases in the air that also dissolve into water, including CO2.


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## ghengis

After typing that last post, and spending a little time reflecting on what I'd said, the lightbulb went off... You may have heard it, it was pretty loud. Anyway, I thought to myself, I thought "Self, you've just gone and nailed the very essence of El Natural aquascaping...d'uh!"

You can see why I don't post in this area too often... :banplease:


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## Alex123

Lol ghengis, did you mean the light bulb when on and not off? If the the light bulb went off, it would make sense that it might have exploded and thus "was pretty loud". I do hope that it went on though as that implies you understand what essabee is saying.

As for my tank, my 10 gallon tank is starting to get cloudy. It's looking to trend like my 20 gallon. I'm going to add the hornworts back in the 10 gallon as well which I took out also around the same time. I can't be sure it's solely due to removal of hornworts as the weather has turned and the house is 10 or 15 degree cooler. Those were the 2 main changes.


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