In nature, water gets some of its CO2 from the atmosphere but mostly from decomposition by bacteria. In natural systems, dead phytoplankton, zooplankton, plants, fish, wastes, and organic matter washed into the system are constantly feeding decomposition and keep CO2 levels stable. Water bodies with large aquatic plant biomass also experience large pH swings throughout the day as plants use up the CO2 during daylight hours and then respire at night. I've seen ponds and lakes that go from a pH of 6 to 9.5 from dawn until noon. In the winter, if too much snow builds up on the ice and blocks light, algae cannot survive and die which fuels more decomposition and the system becomes anoxic causing fish kills.
what carbonates water in nature?
what gives the water in nature CO2? basically my thoughts are that CO2 enters the water though either atmospheric contact or through fishes's (?) respiration. is this correct? this doesn't seem right or else we wouldn't have to dose our tanks with CO2... right?
could someone help me understand this process?
could someone help me understand this process?
1 - 12 of 12 Posts
I've actually been wondering the same thing recently.
If anyone knows please divulge.
I can think of only a few reasons.
The degradation of biomass I.E Leaves and Poo and dead animals, by bacteria, who convert something(whatever it may be) into co2.
Underground vents, geysers, etc.... I'm talking something to do with volcanism here.
And then there is the possibility that most aquatic plants don't actually live underwater year round, they are fully capable of surviving in a dormant stage, but just so as to wait for the flood waters to subside so they may be above water again.
I know there are plants that live underwater at all times, and they may very likely not require much co2.
In the case of plants in specific biotopes that receive biannual flooding, co2 might be required to make them grow underwater, by mimicking the above water environment, but they may not grow underwater in their natural habitat.
Just a wild guess.
If anyone knows please divulge.
I can think of only a few reasons.
The degradation of biomass I.E Leaves and Poo and dead animals, by bacteria, who convert something(whatever it may be) into co2.
Underground vents, geysers, etc.... I'm talking something to do with volcanism here.
And then there is the possibility that most aquatic plants don't actually live underwater year round, they are fully capable of surviving in a dormant stage, but just so as to wait for the flood waters to subside so they may be above water again.
I know there are plants that live underwater at all times, and they may very likely not require much co2.
In the case of plants in specific biotopes that receive biannual flooding, co2 might be required to make them grow underwater, by mimicking the above water environment, but they may not grow underwater in their natural habitat.
Just a wild guess.
I'ld think the correct answer would be, for the most part, nothing to the extant that we carbonate are tanks. Most the aquatic plants I've ever seen in the wild looked worse than those in a poorly maintained low tech tank. Being that most the plants we keep grow emeresed in the wild anyway, they liely just take their carbon from the atmosphere.
The bacteria that decompose organic matter in sediments in lakes produce great amounts of CO2.
the springs here in florida are mainly my basis of comparison. there are some pretty huge 10' to 15' pinwheel like plants that grow in huge bunches. they are really beautiful, but i just dont understand where they get all the carbon from.
-franco, i think your response makes a lot of sense. do you think it would be possible to setup a tank with this kind of decomposition? i like the idea of having a 10 gallon nano that is a completely natural. (that didn't just grow cyanobacteria)
do you think a tank with the right substrate could accomplish this? i want a planted tank that i just have to add water to every once in a while. no chemicals, no forced CO2, no water changes.
-franco, i think your response makes a lot of sense. do you think it would be possible to setup a tank with this kind of decomposition? i like the idea of having a 10 gallon nano that is a completely natural. (that didn't just grow cyanobacteria)
do you think a tank with the right substrate could accomplish this? i want a planted tank that i just have to add water to every once in a while. no chemicals, no forced CO2, no water changes.
Check out to low tech section.do you think a tank with the right substrate could accomplish this? i want a planted tank that i just have to add water to every once in a while. no chemicals, no forced CO2, no water changes.
Its called a Natural Planted Tank. Look under the El Natural section on AquaticPlantCentral.com forums. Also Diana Walstad's book Ecology of the Planted Aquarium is all about soil substrate aquariums. Awesome book and she visits the forum regularly. With a Natural Planted Tank, as the organic matter in the soil is decomposed by bacteria, CO2 is produced. They are wonderful low maintenance tanks if kept low tech. You can do high tech but the faster growth of the plants depletes the nutrients in the soil more quickly. I have a ten gallon and several smaller tanks and bowls set up this way. They are perfect for people who just want an aquatic jungle without the hassle and expense of high tech, heavily planted aquariums. I do a 40% water change every 3 months on the ten gal and my plants, fish, and inverts do fine.
I've read that springwater/wellwater is very high in CO2 due to some geological process but I can't remember what.the springs here in florida are mainly my basis of comparison. there are some pretty huge 10' to 15' pinwheel like plants that grow in huge bunches. they are really beautiful, but i just dont understand where they get all the carbon from.
The "atmospheric equilibrium" for CO2 is supposed to be 3-6ppm but normal levels in most natural freshwater are supposed to be close to 15ppm.
If all that extra CO2 is from decaying plant matter than the water has to be receiving plant matter from terrestrial plants or it would all even out.
Yet most people recommend to attempt to keep a tank in the 30ppm range.....The "atmospheric equilibrium" for CO2 is supposed to be 3-6ppm but normal levels in most natural freshwater are supposed to be close to 15ppm.
.
I guess if you are going to go low tech/low light 15 would be a more reasonable target.
great input. this all make a lot more sense now.
now the big question is: what is the best way to change my substrate (to add topsoil in a 40 gallon tank that already has fish in it?
now the big question is: what is the best way to change my substrate (to add topsoil in a 40 gallon tank that already has fish in it?
Plants are adapted to low CO2. That is why CO2 injection of up to 30 ppm gives the plants an edge over the algae.
The majority of carbon in aquatic systems is allochthonous meaning that it comes from outside of the system. Autochthonous carbon is produced within the water body or stream. Every time precipitation washes into a water body, it carries organic matter (carbon) into the system.
Spring water has a higher CO2 to oxygen ratio than surface waters because it percolates through the soil and then moves downhill over an impermeable layer to escape where that impermeable layer meets the surface. This process depletes the water of oxygen which is why spring water taken directly from the source should be aerated prior to being added to a tank or pond. Springs in which water flows over or through the limestone parent material becomes saturated with dissolved calcium carbonate and bicarbonates giving it a high pH and hardness. Some plants can use carbonates or bicarbonates as a carbon source (vals, ceratophylum spp., egeria densa, elodea canadensis, Chara spp.).
I knew those limnology and watershed management courses weren't a COMPLETE waste of money.
The majority of carbon in aquatic systems is allochthonous meaning that it comes from outside of the system. Autochthonous carbon is produced within the water body or stream. Every time precipitation washes into a water body, it carries organic matter (carbon) into the system.
Spring water has a higher CO2 to oxygen ratio than surface waters because it percolates through the soil and then moves downhill over an impermeable layer to escape where that impermeable layer meets the surface. This process depletes the water of oxygen which is why spring water taken directly from the source should be aerated prior to being added to a tank or pond. Springs in which water flows over or through the limestone parent material becomes saturated with dissolved calcium carbonate and bicarbonates giving it a high pH and hardness. Some plants can use carbonates or bicarbonates as a carbon source (vals, ceratophylum spp., egeria densa, elodea canadensis, Chara spp.).
I knew those limnology and watershed management courses weren't a COMPLETE waste of money.
1 - 12 of 12 Posts
- This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
The Planted Tank Forum
A forum community dedicated to Aquatic tank owners and enthusiasts. Come join the discussion about flora, fauna, health, housing, filters, care, classifieds, and more!
Full Forum Listing
Explore Our Forums
Top Contributors this Month
View All
Kwyet
126 Replies
Creature From The Tank
72 Replies
BarskeReker
45 Replies
Recommended Communities
