How to setup a CO2 system in a Nature Aquarium
I go back to the time,not too many years back,when I used to get motivated by all those wonderful award-winning aquascapes showing lush green carpet plants,background plants in 'Reds' and bright 'Greens'... and end up ordering a whole lot of plants to create my own beautiful aquascape.
Enthusiastically starting off with the layouts and planting the plants meticulously,I used to wait for them to 'bloom' and spread...and then again, wait some more.Over the first week itself,the plants would show signs of fatigue,slowly wilting away,leaf by leaf till only the bare stems were visible and loads of leaves floating on the surface.I used to wonder what went wrong? Good substrate,good filtration,good fertilization and good Lighting.What did I miss?
After some failed attempts at 'Low-cost' aquascaping,I realised that you just can't do without the most important ingredient - Carbon Di-oxide!
The first time I introduced Co2 supply through a can with a diffusser attached (I used a disposable can of Co2 made by ISTA),I could visibly see the difference in virtually 48 hrs flat.The plants looked a lot more 'perkier'...a lot more alive. Within a few days,there were new leaves sprouting where old leaves had fallen off. So,what was happening?
So,why exactly is CO2 so important?
Let's understand why Co2 is so important. Plants depend on Co2 for photo-synthesis - Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight.Photosynthesis occurs in plants, algae, and some species of bacteria. In plants, algae, and cyanobacteria, photosynthesis uses carbon dioxide and water, releasing oxygen as a waste product,which in turn is used by fish and other animals during respiration and give off CO2 as a waste product which is again used up by the fish and animals - thereby completing the cycle.
In nature,in rivers,streams and ponds,CO2 is available in plenty and as such plants thrive in these environs. In an aquarium,the size of the water body is extremely limited and one has to re-create the natural environment within this limited space. Hence, the importance of ensuring the right substrate,adequate and regular dosing of fertilizers,ample lighting and finally adequate CO2 for the plants to thrive.
What you need
All one needs is a 1Kg or 2Kg CO2 cyclinder with a dual gauge meter.The Co2 is released through the use of the dual gauge regulator.Costs vary...here in India these cylinders are typically in the range of INR.3500/- per cylinder. The dual gauge regulator alongwith a Solenoid valve is to be purchased separately and is approx another INR.3500/-. There are single gauge regulators also available from Ocean Free and ISTA in the range of INR.1500/- onwards.The Cylinders are available in regular metal(iron),stainless -steel or aluminium.Iron & Stainless-steel are obviously heavier,while Aluminium is much lighter,but heavier on the pocket!
The single gauges don’t come with decompressor and the gauge only shows the pressure of the gas inside the gas tank. The Dual gauge models show both the pressures of gas inside and one that is going out into the fish tank.The decompressor inside the dual gauge models manages the decrease in the pressure from 70 bar inside the gas tank to about 4 bar going into the diffuser.
A Solenoid / Pneumatic valve is a device that controls the release of the gas from the regulators. It comes in either AC or DC current. AC style Pneumatic valves heat up more than the DC ones, and will allow CO2 to pass through once turned on.Pneumatic valves are controlled by a timer which turns on the lighting at the same time.Thus,with the help of a good timer and a pneumatic valve,one is able to replicate nature's daily rhythm - switching on turns on the Co2 flow along with the lights and switching off turns off the Co2 supply & the lights while turning on the aerator. This is important as during the nighttime,the process of photosynthesis is reversed - Plants also take in Oxygen and give out Co2 - thus competing with the fish and other animals for the available oxygen.
Other accessories you will need
A Check valve enables the gas to flow in one direction only & at the same time prevents the water in the tank from flowing back in to the can/tank.
Bubble counters are important as they allow one to adjust the amount of gas output.Bubble counters are mostly made from glass,however some acrylic ones are also available these days (Ocean Free,ISTA,ADA)
Diffusers finally release CO2 into the water in an appropriate amount that is more readily absorbed by the plants.The most common diffusers are made of glass and ceramic and require a good pressure for the gas to push through the ceramic in to tiny bubbles. Diffusers are placed in the deeper areas of the aquarium,ideally where the water flows downward to maximize their assimilation.
Reactors are a good alternative to Diffusers and can be used in conjunction with external filters. The way they work is that gas is mixed rigorously in the reactor crushing it in to tiny bubbles and dissolving most of it before it is released via the outlet in to the aquarium.
So,all in all you can have your dream aquascape, if you are willing to add just a little CO2 to the rest of the ingredients...all you need is a little of the right 'Gas'!