Waylanderxx
Aquarium Advice Regular
Could an air stone and a bubble powered decoration be bad for plants? I've read on another post that they remove CO2 so the fact that I have them in my tank I'm soon going to plant concerns me
Aeration and plants.
- Thread starter Waylanderxx
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BBradbury
Aquarium Advice Addict
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Using Airstones
Hello Way...
Adding an airstone will increase the oxygen in the water a bit. Oxygen is a plant waste product, so your plants may not do quite as well in the higher oxygen environment. But if you like the bubbles in the tank, a small one won't hurt.
B
Hello Way...
Adding an airstone will increase the oxygen in the water a bit. Oxygen is a plant waste product, so your plants may not do quite as well in the higher oxygen environment. But if you like the bubbles in the tank, a small one won't hurt.
B
dmolavi
Aquarium Advice Addict
I was about to post this same question, but framed slightly differently:
I don't have a heavily planted tank (only about 6 or so in my 56 gallon tank); but I do have an airstone/pump in there, along with 2 200gph HOB filters.
I'm guessing that between the HOBs and the plants, there is sufficient oxygen introduction into the tank, and the airstone is superfluous at this point? (I wouldn't object to introducing a small circulation pump in the tank to keep water moving, but again, with the 2 HOBs, that might be overkill.)
phin
Aquarium Advice FINatic
It is my understanding that air bubblers, as well as low water levels that cause splashing and bubbles on the return from HOB filters causes the off-gassing of CO2.
I don't know the extent, but it would be my guess that on a lightly planted tank my guess would be that it won't make a difference.
I don't know the extent, but it would be my guess that on a lightly planted tank my guess would be that it won't make a difference.
OP
OP
Waylanderxx
Aquarium Advice Regular
With these two bubble making things turned almost off I'm guessing I still have too much aeration correct?
BBradbury
Aquarium Advice Addict
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Tank Filtration
Hello d...
Airstones do little to get oxygen into the tank water and release carbon dioxide. The bubbles are small and even a lot of them don't create enough surface movement.
Filtration devices will do a much better job of gas exchange. Your filter simply needs a gallon per hour (gph) rating 6 times the volume of the tank in gallons. So, if I have a 30 gallon tank, I want a filter large enough to turn over at least 180 gallons of tank water per hour. More filtration is a bit better, but if you perform large, weekly water changes, you don't need much added filtration, because the filters are just filtering water that's already clean.
Keep in mind that mechanical filters are simply taking in toxic water and replacing it with water that's a bit less toxic.
B
Hello d...
Airstones do little to get oxygen into the tank water and release carbon dioxide. The bubbles are small and even a lot of them don't create enough surface movement.
Filtration devices will do a much better job of gas exchange. Your filter simply needs a gallon per hour (gph) rating 6 times the volume of the tank in gallons. So, if I have a 30 gallon tank, I want a filter large enough to turn over at least 180 gallons of tank water per hour. More filtration is a bit better, but if you perform large, weekly water changes, you don't need much added filtration, because the filters are just filtering water that's already clean.
Keep in mind that mechanical filters are simply taking in toxic water and replacing it with water that's a bit less toxic.
B
dmolavi
Aquarium Advice Addict
I've got lots of chem/bio/mech filtration running between the two filters (Purigen, polishing pads, carbon, wheels, etc), and my weekly water tests show the water is pretty dang good (save for the nitrates, which are a little high for my taste, but I've read that the API test kits read high on nitrates anyway).
I may try shutting down the air pump, as it's getting quite noisy; though I'm concerned the Flourish Excel I use a few times a week for the plants might decrease the amount of dissolved O2 in the water, though I don't see anything on SeaChem's website indicating as much.
aqua_chem
Aquarium Advice Addict
Airstones function to increase surface agitation. Surface agitation causes gas exchange between the air and the water. This drives the levels of CO2 and oxygen in the water towards their equilibrium concentrations.
SO, if your levels of CO2 are high than their normal equilibrium levels (in the case of CO2 injected tanks), the an airstone will reduce CO2.
If your CO2 levels are lower than equilibrium levels (like if your plants have used it all), it will increase your CO2 levels.
Essentially, if you're not injecting CO2, don't worry about a bubbler.
SO, if your levels of CO2 are high than their normal equilibrium levels (in the case of CO2 injected tanks), the an airstone will reduce CO2.
If your CO2 levels are lower than equilibrium levels (like if your plants have used it all), it will increase your CO2 levels.
Essentially, if you're not injecting CO2, don't worry about a bubbler.
phin
Aquarium Advice FINatic
Thanks. Thats some useful info. On my tank, where I don't have CO2 injection and only dose with excel, additional surface agitation will ensure that I have equilibruim concentrations of CO2 at all times. 3ppm?
phin
Aquarium Advice FINatic
An academic paper on CO2 concentration. This may be interesting to some of you.
http://www.pwtag.org/researchdocs/Used Ref docs/52 Carbondioxide in water equilibrium.pdf
http://www.pwtag.org/researchdocs/Used Ref docs/52 Carbondioxide in water equilibrium.pdf
At room temperature, the solubility of carbon dioxide is about 90 cm3 of CO2 per 100 ml water (cl/cg = 0.8).
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aqua_chem
Aquarium Advice Addict
The concentration of co2 at equilibrium is significantly below saturation. This is why we have to inject so much co2 relative to the equilibrium concentration when we use higher lighting levels.
But yes, co2 levels in an aquarium are between 3-7 ppm, varying on a number of factors, especially temperature. There is some disagreement on the number, but its pretty minor in the long run (I've seen an entire thread of people arguing about whether it was 3 or 5).
But yes, co2 levels in an aquarium are between 3-7 ppm, varying on a number of factors, especially temperature. There is some disagreement on the number, but its pretty minor in the long run (I've seen an entire thread of people arguing about whether it was 3 or 5).
phin
Aquarium Advice FINatic
Is there a significant difference in CO2 levels at 80F vs 76F? I mean, if I'm not currently injecting but would like to maximize my CO2 equilibrium what are the optimal factors? What temperature? What pH? What KH?
I know i'm talking tiny amounts, 3ppm vs 7ppm (especially when CO2 is injected at amounts 10x this), but if I had the choice, and the time and effort was negligible, I'd rather have 7ppm CO2 + Excel vs. 3ppm CO2 + Excel.
aqua_chem
Aquarium Advice Addict
The benefit you would see from 2 ppm increase in co2 would not warrant the changes. You simply won't see a tangible advantage from it.
phin
Aquarium Advice FINatic
I'm talking 4ppm here!
Do you think it would be cost effective to CO2 inject my 18 gallon tank (10x20x20) vis-a-vis only excel supplementation?
dmolavi
Aquarium Advice Addict
I'm talking 4ppm here!
Do you think it would be cost effective to CO2 inject my 18 gallon tank (10x20x20) vis-a-vis only excel supplementation?
Probably not, IMHO. I use Flourish Excel on my lightly planted tank and the plants are doing fine (so long as my nibblers aren't nibbling them away). I may move from the liquid to the tabs, though, since the tabs will get right at the root.
phin
Aquarium Advice FINatic
Flourish makes excel tabs? I know they make flourish root tabs, but those are for nutrient supplementation, not carbon supplementation. Or do the flourish tabs contains a carbon soruce as well?
dmolavi
Aquarium Advice Addict
Good catch..no, they don't. Guess I'll be supplementing my Excel with the tabs. Seachem. Flourish Tabs vs Seachem. Flourish Excel
aqua_chem
Aquarium Advice Addict
Just to clarify, you're asking if it's more cost effective to supplement with Excel as opposed to CO2?
It's not really a matter of cost effectiveness. You either do CO2, or you do something that tries to get some of the benefit of CO2 to avoid actually doing CO2. As a general rule of thumb, I usually say that CO2 is about 3x as effective as Excel, and in a high light situation it's not even substitutable. On an 18 gallon tank, DIY CO2 is still a viable option (although you're just getting to the point where it will start to fall off in effectiveness).
Link119
Aquarium Advice Freak
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Gases dissolve better int liquids at lower temperatures, so keeping the temperature at 76F rather than 80F will help increase the amount of CO2.
