CO2 Diffusion Methods

Hello and welcome back,

Anyone that is in this hobby for the pants will already know that CO2 is a very essential part of growing healthy plants. The diffusion and distribution of CO2 to plants can be carried out in many ways.

One has to firstly decide which path to follow. Gas CO2 or liquid CO2. I have seen planted aquariums equally beautiful with both CO2 sources, however, it should be said that the first is more costly but the second is slower. Liquid CO2 is rarely used alone and it is mostly used to complement the pressurized CO2 already added to the aquarium. Liquid CO2 will also inhibit growth in certain plant species like Vallisnerias.  

1. Glass Diffuser: this is the most common diffusion method. There are different quality glass diffusers with the main difference being the ceramic disc which defines the size and number of the CO2 bubbles. ADA diffusers are among the best, but cheaper one like Rhinox found on eBay are also very efficient and taking into account the price difference, more value for money. Different sizes, different shapes, even different materials define the price. Some even have a bubble counter incorporated.

2. Inline Diffuser: an inline diffuser is a small accessory that you connect to the inline/outline tube of your external filter and produces finite bubbles just like a glass diffuser without having any equipment in the tank. If it is connected on the outflow of your filter, then the bubbles are pushed out of and are visible. However, if you connect it on the inflow of the filter, the bubbles get sucked into the propeller of the filter and are dissolved completely, so no visible bubbles coming out, just like a reactor. Sometimes there is CO2 buildup in the filter and every now and then some CO2 is blown out the filter outflow. Personally I prefer using an inline atomizer on the inflow of the filter, I have done so for quite some time now without any problems at all. Less equipment in the tank and no bubbles.

3. Reactor: just like an inline diffuser connected to the inflow of a filter, a reactor is a compartment on the inflow or outflow of the filter that will dissolve the CO2 completely. No bubbles are visible and it is said to be the most effective method of CO2 dissolution, even though it will inhibit flow sometimes. There are ready made ones and if you are a DIY person there are simple instructions you can follow to build one yourself. Rex Grigg has a nice setup guide you can follow.

4. Atomizer: an atomizer is very similar to a glass difusser in the sense that it is situated in the tank and expels tiny bubbles just like mist. This is a lot more efficient than an average glass diffuser and maybe better than the expensive ADA ones. It is not as beautiful as an ADA glass diffuser but it will do the job.

Online shops you can get such equipment:
1. CO2 Art-based in UK you can find almost anything ralated to CO2 apart from ADA
2. Aquarium HK-based in Hong Kong, this is where you find reactors, Rhinox diffusers & atomizers
3. The Green Machine-if you are interested in the ADA products here is where you can find them
4. Aquaessentials-based in UK there are always a few CO2 diffusers and atomizers
5. eBay

Thank you for reading. For any questiosn please leave a comment.