Carbon is the most vital thing when an organic life is considered, aquatic plants also being organic creatures like us require constant supply of carbon for sustaining growth and reproduction. well we all know that carbon is fixed inside plant cell during light independent phase of photosynthesis to form basic sugar glucose which is later used for production of other complex sugars, fat, proteins and ofcorse in respiration to generate energy.
First, let’s see how plants grow in nature without any human interference-
carbon is mainly available to them in the form of free CO2 and bicarbonate (HCO3-) in water bodies. Plants are adapted to use free CO2 way better than the ion due to less energy investment in doing the former.
In nature plant growth is limited by both light and co2 at the same time (yeah Liebig’s Law doesn’t hold true! look for tropica article on light and co2). We mainly find abundance of plant diversity in streams rising from underground which is loaded with ample amount of co2. When water passes through aquifers underground bacteria respires off co2. As there is no space to escape ,co2 remains in the water which helps in the growth of plants above.
Why do we generally find monoculture in ponds? Due to limitation of co2 the strongest species survives by capturing most amount of co2. (now probably it makes sense why with DIY yeast system you could grow few plants and other couldn’t grow when kept together no matter how much light and fert you supplied!).
we all know diffusion rate of CO2 in water is 10,000 times slower than in water, so inspite of co2 supplied by the bacteria they had to adapt few physiological changes to overcome carbon limitations-
1. They have thin and dissected leaves which increases surface to volume ratio helping in easy co2 uptake.
2. They have modified parenchyma cells known as aerenchyma that acts as air channel to trap respired co2 for future use.
3. They often exhibit hexagonal packing of cells which is the best possible way to build a structure with least resource used.
4. Many species can use bicarbonate in the time of crisis.
Now the question is can plants grow in our aquarium with no supply of co2 from outside??
The answer is YES. They get co2 from fishes, little amount diffused from air and contributed by bacteria thriving in the substrate. BUT the growth rate in simply not enough if you are an aspiring aquascaper who dreams day and night to make an Amano style tank!
Here goes a little fact- Excel (a co2 supplement from Seachem) based tank has 4 to 5 times (400% to 500%) better growth rate than a non co2 tank, and a pressurized co2 enriched tank can exhibit as high as 15 to 20 times (15000% to 20000%) increase in biomass compared to a non co2 one!
We mostly supply enough light and nutrient but fail to add enough co2 in our tanks. Co2 is the most important limiting parameter in our tanks.
Now coming to algae problem we all have this notion that algae proliferation occurs due to high level of nutrients!! absolutely not!!
It’s due to excess light and low co2 that prevent plant growth which gives algae an edge in their survival. Without Co2, photosynthesis cyclic reactions can not occur efficiently which generates reactive oxygen species (ROS) that damages the plant. If you are having hair algae and BBA problems please try to lower you light intensity and bump up co2 levels- guaranteed positive outcome!
It is also advised to maintain a constant level of co2, which is the biggest problem faced in DIY yeast system. unlike other nutrients, Co2 levels can drastically drop from 30 ppm to 3 ppm in just 30 mins in a healthy tank if supply is not steady. Switch on your co2 15 to 20 mins before you switch on the lights. Co2 reaches a decent level within that time.
We don’t add much Co2 in the fear of getting our beloved fishes and shrimps killed, but trust me maintaining 40 ppm of co2 is very much safe and that is the recommended level of co2 for a planted tank. (Co2 level measurement and process of delivery will be discussed in coming issues)
Why do plants seem to grow well in water change days?!
Simply because tap water is rich in co2 (15 to 20 ppm) and other micro nutrients. Plus plants exposed to air traps air in their aerenchyma that can be used later on. So it is advised to let your plants ‘breath’ for few mins during water changes!
A tank can be maintained without any substrate as well if you supply enough co2 and nutrient in the water column. Consider going through hydroponic techniques.
So, the bottom line is if you are going to make a successful planted tank please first make sure you have a good co2 system, other parameters can be managed later. Once you start adding co2 it is like a drug addiction which is hard to get rid off, those lovely pearling leaves and astonishing growth surely makes the life worth living. Amano himself killed tank full of fishes by adding excess co2 and it took him almost 10 years to realize the complete use of external co2. So, it is never too late! Add co2, to be precise add life to your tank! Thank you.
If you find anything wrong and misinformed , please free to point out..I wrote everything from my experience and knowledge..9007737733 is my no..you can get in touch with me if you have any specific quarries. thank you..happy aquascaping
