CO2

sharkweek178

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I'm going to start a planted tank soon. I've been reading up on aquascaping. What can you tell me about CO2 injections?
Is it worth the effort and expense?
What about a DIY set up like I've seen using soda bottles and sugar and yeast mixtures?
I'm getting the impression that liquid CO2 is kind of a snake oil. Am I wrong?
And most importantly, how can this be done in a way that is safe for the fish?
 

Byron

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Adding CO2 as diffused CO2 (or homemade from yeast) is now believed to affect fish (not at all surprising). The so-called liquid carbon supplements are as bad and probably much worse. They are derived from the toxic disinfectant glutaraldehyde, and if you want to know how deadly that is, read up on it.

If you have fish in the tank, you should not, in their best interest, consider adding CO2. CO2 occurs naturally not only from the respiration of fish, plants and some bacteria, but at night the breakdown of organics in the substrate can add a significant amount. The plants will then use this as soon as it is "daylight," meaning the brightest tank lighting period. I have observed issues with my fish, cories especially, from the increased level of CO2 at night, and I do not add any form of CO2.

If you are running a high-tech system, with mega intense light and daily fertilizing, then CO2 will benefit the plants. But a low-tech or natural method planted tank where the fish are priority will be fine without adding carbon.
 
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sharkweek178

sharkweek178

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Adding CO2 as diffused CO2 (or homemade from yeast) is now believed to affect fish (not at all surprising). The so-called liquid carbon supplements are as bad and probably much worse. They are derived from the toxic disinfectant glutaraldehyde, and if you want to know how deadly that is, read up on it.

If you have fish in the tank, you should not, in their best interest, consider adding CO2. CO2 occurs naturally not only from the respiration of fish, plants and some bacteria, but at night the breakdown of organics in the substrate can add a significant amount. The plants will then use this as soon as it is "daylight," meaning the brightest tank lighting period. I have observed issues with my fish, cories especially, from the increased level of CO2 at night, and I do not add any form of CO2.

If you are running a high-tech system, with mega intense light and daily fertilizing, then CO2 will benefit the plants. But a low-tech or natural method planted tank where the fish are priority will be fine without adding carbon.
The safety of the fish is really my main concern. I don't want just a water garden.
Something I considered was adding CO2 while I grow plants during the cycle and then to discontinue using it before the fish are added. But I'm thinking if the plants become dependent on and grow to a certain size based on a higher level of CO2, that could be a mess when it drops to a lower level.
 

Byron

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The safety of the fish is really my main concern. I don't want just a water garden.
Something I considered was adding CO2 while I grow plants during the cycle and then to discontinue using it before the fish are added. But I'm thinking if the plants become dependent on and grow to a certain size based on a higher level of CO2, that could be a mess when it drops to a lower level.

Correct. Plants will grow in response to the environment. Each species requires a minimum level of light intensity to drive photosynthesis, but the plant cannot "grow" unless the 17 nutrients it requires are also available. If everything is available in sufficient levels, the plants will grow "full out" so to speak, but as soon as one factor in this balance is missing, photosynthesis (growth) slows and may even stop. At that point, algae has the advantage and we see problems. So it is better to introduce a new plant into the environment it is expected to bein for its life. This is not to say it cannot manage periods of more intense growth if "x" should improve, but there is always then the risk that it will not rebound once "x" or something else is insufficient.

I have always started with the light. Recognizing that fish do not like overhead light to begin with, and that some species will be stressed if it is bright, I select what most would term low/moderate light, and I always have floating plants. Then I decide on lower plants, and if I want these they must be suited to the light I offer them. It is simple enough to add nutrient supplements--the key word here is "supplements." The biological system supports the fish and plants in a balance, and I add "incentives" for the plants if these are needed and always assuming they will not adversely affect the fish, which come first.

One can have fairly heavily planted tanks doing this, as the photos of some of mine show.
 

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StevenF

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liquid CO2 sold in stores is a synthetic chemical (glutaraldehyde C5H8O2) that is commonly used as a disinfectant. It is similar to chemical plants make. It has been claimed hat plants can use it as a source of carbon instead o CO2. I have seen no documented evidence that it does help plants. Also too much of it is toxic to fish and can kill them. Also some plants are damaged by it.

Fish exhaile CO2 and mixing air with water will cause some CO2 from the air to get into the water. So moving water is better than stagnate water. So some tanks may have enough CO2 in the water. But as of right now there is no way to measure CO2 in the water. There are some test kits that claim to measure it but they only work with pure water. Unfortunately aquarium water is never pure.

Other than light water and CO2 plants need minerals to grow. If just one single nutrient is missing you will not get any plant growth and the plant will eventually die and you will have algae issues. There are 14 nutrients other than CO2 that are needed for growth. If you cannot get floating plants to grow you have a fertilizer issue. Floating plants get all the CO2 they need from the air.

Some people have tap water with enough in it for good plant growth with a regular water change. other do very small or no water changes with the coal of using fish waist as a fertilizer. Most people have to use a fertilizer to grow plants. In my experience most plant problems are due to one or more nutrients in short supply rather than CO2. So you may want to try a fertilizer without liquid CO2 first before injecting CO2.

If you do decide to use CO2 there are2basic ways to do it:

  • One methode is called passive CO2. This involves place an open inverted bottle in the tank with nor air in it. ig is then filled with CO2. The water then naturally pulls the CO2 out of the bottle as needed. When the inverted bottle is empty you refill it. Passive CO2 is self regulating and is very efficient and won't kill your fish with excessive CO2 levels. The CO2 can come sugar test reaction, acid carbonate reaction, or pressurize bottle. in my opinion this is the best methode to use.
  • Others use CO2 diffusers but CO2 flow and pH need to be frequently checked to avoid getting to much CO2 into the aater. if that happens the fish die. Diffuser work best with pressurized CO2 gas cylinders
 
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sharkweek178

sharkweek178

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Correct. Plants will grow in response to the environment. Each species requires a minimum level of light intensity to drive photosynthesis, but the plant cannot "grow" unless the 17 nutrients it requires are also available. If everything is available in sufficient levels, the plants will grow "full out" so to speak, but as soon as one factor in this balance is missing, photosynthesis (growth) slows and may even stop. At that point, algae has the advantage and we see problems. So it is better to introduce a new plant into the environment it is expected to bein for its life. This is not to say it cannot manage periods of more intense growth if "x" should improve, but there is always then the risk that it will not rebound once "x" or something else is insufficient.

I have always started with the light. Recognizing that fish do not like overhead light to begin with, and that some species will be stressed if it is bright, I select what most would term low/moderate light, and I always have floating plants. Then I decide on lower plants, and if I want these they must be suited to the light I offer them. It is simple enough to add nutrient supplements--the key word here is "supplements." The biological system supports the fish and plants in a balance, and I add "incentives" for the plants if these are needed and always assuming they will not adversely affect the fish, which come first.

One can have fairly heavily planted tanks doing this, as the photos of some of mine show.
Nice. Those are beautiful.
Another idea I thought of is adding floating plants but creating floating ring dividers to create separate areas without floaters so that plants that need a higher level of light can get it.
 
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sharkweek178

sharkweek178

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liquid CO2 sold in stores is a synthetic chemical (glutaraldehyde C5H8O2) that is commonly used as a disinfectant. It is similar to chemical plants make. It has been claimed hat plants can use it as a source of carbon instead o CO2. I have seen no documented evidence that it does help plants. Also too much of it is toxic to fish and can kill them. Also some plants are damaged by it.

Fish exhaile CO2 and mixing air with water will cause some CO2 from the air to get into the water. So moving water is better than stagnate water. So some tanks may have enough CO2 in the water. But as of right now there is no way to measure CO2 in the water. There are some test kits that claim to measure it but they only work with pure water. Unfortunately aquarium water is never pure.

Other than light water and CO2 plants need minerals to grow. If just one single nutrient is missing you will not get any plant growth and the plant will eventually die and you will have algae issues. There are 14 nutrients other than CO2 that are needed for growth. If you cannot get floating plants to grow you have a fertilizer issue. Floating plants get all the CO2 they need from the air.

Some people have tap water with enough in it for good plant growth with a regular water change. other do very small or no water changes with the coal of using fish waist as a fertilizer. Most people have to use a fertilizer to grow plants. In my experience most plant problems are due to one or more nutrients in short supply rather than CO2. So you may want to try a fertilizer without liquid CO2 first before injecting CO2.

If you do decide to use CO2 there are2basic ways to do it:

  • One methode is called passive CO2. This involves place an open inverted bottle in the tank with nor air in it. ig is then filled with CO2. The water then naturally pulls the CO2 out of the bottle as needed. When the inverted bottle is empty you refill it. Passive CO2 is self regulating and is very efficient and won't kill your fish with excessive CO2 levels. The CO2 can come sugar test reaction, acid carbonate reaction, or pressurize bottle. in my opinion this is the best methode to use.
  • Others use CO2 diffusers but CO2 flow and pH need to be frequently checked to avoid getting to much CO2 into the aater. if that happens the fish die. Diffuser work best with pressurized CO2 gas cylinders
I think I would be pretty happy to keep it simple and go without the CO2. Any recommendations for liquid fertilizers and root tabs?
 

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