# To aerate or not to aerate....



## najicta (Sep 5, 2012)

Hi all! I have an established 30gallon tank with 3 live plants, a large piece of driftwood and a host of wonderful fish: A betta (Norbert), a baby bushynose pleco (Pete), 3 diamond tetras, 3 green neon tetras, 3 brilliant raspboras, 2 harlequin raspboras, 2 pristellas, 3 zebra danios, 4 lampeye kilis, 3 platys (1 male, 2 female), and 3 shrimp (1 ghost shrimp - Jean-Ralphio & 2 Amanos - Matt Damon & 'Lil Sebastian). I use a simple, pebble-style substrate. My filter is a Penguin Bio-Wheel 150, which does a pretty good job of breaking the surface tension of the water. My question is, would my tank benefit from an air-stone or other bubbler? I remember using one in a non-filtered betta tank I had when I was little, but I don't particularly know if it is necessary in my current one... I Just found a random air pump in my bag of tank-goodies that I don't even remember purchasing! Any pros or cons to using it? Thanks! :grin2:


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## big b (Jun 28, 2014)

It would aerate the water a bit but it wouldn't do much else I think.


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## clumsycarp (Jul 28, 2015)

it has been my experience that aeration is always a benefit.diffusers (not bubblers.lol) should be placed at the bottom of the tank so that the rising bubbles will pull the water with the greater amount of co2 to the surface to expel it.water does have a saturation point where it can no longer take in oxygen but it is doubtful that you will reach it.
fish like oxygen....


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## jccaclimber2 (May 6, 2012)

There are very few situations where aeration is bad, and many where it is good.

You aren't trying to expel CO2, you're trying to help get more O2. Similar, but not the same.

CO2 and O2 levels are surprisingly not constant through the tank. The main advantage of an airstone or bubbler is the water movement it causes, although the surface area of the bubbles doesn't hurt. Get the water that needs O2 to the surface and it will pick some up.

You can do a similar thing with a circulation pump, but the airstone is generally cheaper and easier.

Hard to do without a lot of maintenance, but it looks really cool when plants start pearling with excess O2.


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## BBradbury (Apr 22, 2011)

Hello naj...

Air stones don't do a good job of mixing oxygen into the water. The tiny bubbles don't agitate the surface much. If you remove the air stone and place the end of the plastic tube at the bottom of the tank, then you'll get the surface movement needed to mix more oxygen into the tank water.

Remember that a high oxygen environment is good for the fish, but not for the plants. Oxygen is a plant byproduct. That means the plants work to remove it from the water.

B


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## jccaclimber2 (May 6, 2012)

BBradbury said:


> Hello naj...
> 
> Air stones don't do a good job of mixing oxygen into the water. The tiny bubbles don't agitate the surface much. If you remove the air stone and place the end of the plastic tube at the bottom of the tank, then you'll get the surface movement needed to mix more oxygen into the tank water.
> 
> ...


I may be mis-interpreting what you are saying, but here goes anyways:

1) The bubbles coming out of the airstone don't exchange much O2, but they do a good job of circulating water in the tank. That circulation of the O2 rich water at the surface back down, and the comparatively depleted water at the bottom to the top for gas exchange. In this manner they do a good job of getting O2 in to the water.
2) A large number of airstone sized small bubbles does a better job of moving water than the same amount of air running out of the end of a tube. If your tube with no airstone is moving more water than the same tube with an airstone you probably have a blown diaphragm or check valve in your air pump. I've yet to see someone put an airstone anywhere other than near the bottom of the tank.
3) Oxygen is a plant byproduct, but all of the other aerobic processes in the tank (fish, beneficial bacteria) really love it. People go to a lot of trouble with wet/dry filters to get their O2 up. I've seen two cases where dissolved oxygen has been pushed above equilibrium in an aquarium. In both cases it was plants (with CO2 injection) doing it, and the plants were quite happy in both cases. If you have any documentation where high O2 hinders aquarium plant growth I would love to see it.
4) Incidentally unless you have a lot of decomposition in the tank and very little surface exchange (this happens in some lakes), your plants are also keeping your CO2 below equilibrium and the extra circulation will (ever so slightly) increase that .


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## BBradbury (Apr 22, 2011)

Hello jcc...

Your post was a bit long for me. Here's what I said. An environment high in O2 isn't ideal for plants, but good for fish. If you agitate the surface water too much you'll drive off carbon dioxide slowing plant growth. 

B


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## jccaclimber2 (May 6, 2012)

Here's the short version:

I'm not convinced high O2 hinders plants significantly. Even if it did, the indirect benefits of high O2 and circulation will benefit the plants more than the O2 might directly harm them.

In a non CO2 injected tank surface agitation *increases* CO2 during the day.


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## clumsycarp (Jul 28, 2015)

I think that instead of trying to show folks how brilliant we are and how much we think we know about this ; how about folks start paying attention to mother nature.
because I see some stuff that is pretty far off.


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## jccaclimber2 (May 6, 2012)

clumsycarp said:


> I think that instead of trying to show folks how brilliant we are and how much we think we know about this ; how about folks start paying attention to mother nature.
> because I see some stuff that is pretty far off.


Please elaborate so that we can try to discuss and learn something.


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## clumsycarp (Jul 28, 2015)

look at deep lakes. the lower limits have far less life than the upper limits.that is because the lower part does not get turned over as much as the upper levels and has a higher co2 level and a much lower o2 level. lakes need some pretty heavy winds to turn them over.shallow lakes get turned over much more often and have higher o2 levels. 
in an aquarium the turnover hast to work the same way as nature to a degree..turnover is important.actually air diffusers are much better at aerating a tank than say a HOB or canister type filter.the water really does not absorb oxygen from the bubbles. it all happens at the surface. that is where the "gas exchange" takes place.a diffuser set on the bottom will allow the rising bubbles pull water from the bottom and push it to the top.as the bubbles burst co2 is released and o2 get absorbed.the current created by the bubbles will also push the oxygenated water to the lower levels..a hob or canister doesn't create enough surface disturbance to aerate like a diffuser would.
no diffusers in the lakes you say..the wind acts as the diffuser. i have been at sea and have lived all my life on the shores of one of the great lakes.as the winds pick up so do the waves..the more wind the greater the wave action.the lake is being disturbed a great deal.the crashing waves send currents to the deeper waters , pushing them up to the surface.the waves also create a great deal of surface agitation that releases the co2 and allows for the absorption of o2.
in an aquarium stocked with fish if you cut off any form of aeration it won't be long before you start losing fish.try this experiment..take one of your stocked tanks running a hob filter. turn the filter off until the fish start coming to the surface for air.turn the hob back on and time how long it takes the fish to go completely back to normal activity. later put a diffuser in the tank running at a good rate.turn off the filter.the shut down the diffuser.wait for the fish to come up for air.turn the diffuser back on and time how long it takes for them to go back to normal.which takes the longest time.
it is all about the gas exchange. and the smaller the bubbles , the better the gas exchange.
as for plants in the tank.it has never been my experience that good aeration is harmful to aquatic plants.plants do produce oxygen,no doubt about that.one of the first things we learn about the plants.but that is only when the lights are on...when the lights go out,the plants will consume o2 and actually give off co2. so make sure planted tanks are aerated at night.
the more man looks at how mother nature does thing , the better understanding he will have on how to care for his captive creatures.
sometimes i really hate trying to help folks..i can never keep thing short.lol


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## FishFlow (Sep 13, 2011)

Can't add anything but a thank you for generating a great discussion.


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## clumsycarp (Jul 28, 2015)

there will always be those of us that do not agree on topics.much of what i state comes from reliable sources and my own experiences...
no ; i am not well educated but over the past decades there are a lot of things that i have learned..i am certainly not always right about everything .
the bubble information came from 2 sources...an aquatic biologist friend of mine and Dr. William T. Innes's book Exotic Aquarium Fishes.


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## jccaclimber2 (May 6, 2012)

clumsycarp said:


> look at deep lakes. < snip >


Sounds like we're in agreement. I didn't want to go into the case where decomposition results in above steady state values of CO2 as I don't think this is as relevant to home aquaria in a regularly cleaned tank. If of course you take (also Dr.) Diana Walstad's approach it can happen, but I think few people do this. On that note, even Walstad advises water circulation.

I don't have the data, but somewhere Walstad has some interesting data of CO2 and O2 concentrations by hour in lakes. It shows the CO2 rising at night, and getting dragged down quickly during the day. I suspect that CO2 production rate is relatively constant at lower layers with CO2 consumption being relatively constant during the daytime hours, but at a much higher rate than production.

Another question, in spring time when there is still significant decomposition, but much less consumption due to plants just starting to grow, is growth much faster due to more CO2 per plant?


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## aquatic-life (Nov 25, 2012)

Hey! 
I don't want to be rude or something but you have a lot of problems in your population,all tetras should be kept in a number of 6 minimum they are school fish.. for example green neon tetra should be much more for them to be relaxed in your tank same for the rasbora and danio also.. But I am afraid if you want to go up to the required number of fish per species you will be "severely" over populated.. Stick to 2 or max 3 species and get them like 6-8 fish per species,they will look much better and never hide in case you are facing some fish hiding in your tank.

As for aeration I never used a bubbler,I only used it in a hospital tank,since you have live plants it's okay count on them they are creating for you a perfect cycle,from giving oxygen to helping pollution problems also. Just be sure that the filter you are running its output is directed to the surface in order to make some movement this will be more than enough.


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## Summer (Oct 3, 2011)

Interesting read. Going back to the original question, i dont think an air stone could hurt anything so there is only benefit from it even if its just a little.


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