I dont see the difference...

[Tilmo2180]

Using a Co2 reactor adds Carbon Dioxide to the water through a defuser (at a rate of about 2-4 bubbles per second, i think), right? This Co2 is needed for plants to conduct photosysthesis so they can live, this much I know.
There is naturally Co2 in the air as that is what all air breathing mamamls produce when they breathe...

Therefore if you areate your tank with a regular air pump you would in essence be adding small levels of Co2 to your tank, right? I have been told by my LFS that there were studies done that proved that it does not matter if you areate with 100% Co2, 100% o2 or just plain air it does not alter the saturation levels of Co2 or o2.

I read alot about how you "need" a Co2 system for a planted tank to grow properly. But what my LFS said makes sense to me. My LFS uses no Co2 areation and his tank (mostly anacharis) is doing just fine.

Maybe I am missing something, can someone clarify for me please.

[Algenco]

Your lfs is full of ----! There have been numerous people that have killed their fish with too much CO2. CO 2 outgases much easier than O2 Areation will release CO2 and incorporate O2 into the water.

[dev]

If I remember correctly - a fish tank with moderate surface movement will usually dissolve around 4-5 parts per million CO2 from the air.

If you apply enough aeration, the agitation will cause the dissolved CO2 to escpape into the air. It will almost completely deplete the water of CO2, leaving only 0.5 ppm.

This effect can in fact be used to decide how much CO2 you had in the water to begin with, by measuring the pH before and after aeration.

Your LFS could be right in a way, it does not matter so much what kind of gas you use to stir up the water. It's the agitation on the surface that becomes the deciding factor. The result will be the same however, CO2 will escape into the air, and the water will be oxygenated.

A diffusor works completely differently by letting a gas dissolve into the water without creating much agitation, or letting the water come in contact with air.

When you add CO2 to your tank you are usually aiming for 20-25 ppm. This cannot be achieved by any other means than letting the gas diffuse into the water (there are however several ways to do this).

[Tilmo2180]

So, the bubbles that aggitate the top are off gassing the Co2 and leaving in the o2, right? :confused:

Therefore the air pump adds o2 and removes Co2, so I should use both then or just remove the air pump all together?

Thank you guys for clarifying that for me...

For a 75g tank I read somewhere that I would need a bulk Co2 tank setup not just a little DIY 2L bottle setup, right? I have seen many types, what type works best?

I just want to make my finned and leafy friends as happy as possible.

[RobbieG]

Anachris will grow under almost any conditions. No Light - No CO2 - No Substrate - No Problem.

[dev]

Therefore the air pump adds o2 and removes Co2, so I should use both then or just remove the air pump all together?

The air pump will remove the CO2, so you should remove it. In a well planted tank the plants will provide enough oxygen. If the conditions are good, plants will dissolve more oxygen into the water than you would be able to get through aeration.


For a 75g tank I read somewhere that I would need a bulk Co2 tank setup not just a little DIY 2L bottle setup, right? I have seen many types, what type works best?

Any CO2 is better than no CO2 - and if your DIY is giving 3 bubbles per second, you are doing quite well already. You might still find that a pressurized will work better for your tank. It's much easier to regulate the flow, and keep a stable CO2 level with a pressurized system - and it is much less of a hassle.

As for the actual equipment, I don't know what is available in your area. Hopefully someone else will be able to make a reccomendation.

[Lady Hobbs]

Additional co2 just seems to grow greener, fuller and more lush plants. People claim to see a huge growth spurt after adding it.

[Bill M.]

I have switched from my stock lighing to a 20 watt flora-glo bulb, and it is surprisingly dimmer, but the plants have been growing amazingly and the tank looks more natural with a dimmer light.... to me, lighting has done more than CO2 injection...

[Drumachine09]

I have switched from my stock lighing to a 20 watt flora-glo bulb, and it is surprisingly dimmer, but the plants have been growing amazingly and the tank looks more natural with a dimmer light.... to me, lighting has done more than CO2 injection...


The bulb isnt dimmer, it is just in a different spectrum. You probobly had one in the 6500-6700 k range (pure whiteish), and you probobly ended up wtih about the 9000k range.

[dev]

I have switched from my stock lighing to a 20 watt flora-glo bulb, and it is surprisingly dimmer, but the plants have been growing amazingly and the tank looks more natural with a dimmer light.... to me, lighting has done more than CO2 injection...


Well, you really do need a bit of both :) I saw a very nice table once, showing how different combinations of CO2 levels and light intensity was found to affect photosynthesis. I'll see if I can find it again...

The Hagen Flora Glo is a low kelvin tube (2800K) with a lot of light in the red spectrum. Since it does not contain a full spectre of light it will appear dimmer to the eye, while providing about the same amount of light. Red light is known to mean much for photosynthesis, but has the drawback on not going very far in water.