So you have decided to set up your new aquarium or convert your existing aquarium into a heavily planted freshwater aquarium and try out your aquatic green thumb. You have done your research, decided what plants you’re going to plant, selected your lighting and planted aquarium substrate, and you’re ready to go. There may be just one lingering question, one thing you aren’t familiar with in your process and heck you don’t even know if you need it or not. Do you need to add some sort of CO2 source to your new planted aquarium? The answer to that question is a 100% solid “maybe”.
Your need to supplement with CO2 in your planted aquarium will be driven by the requirements of the plants themselves. Will the plants grow more quickly and have better color if you are supplementing with CO2, yes most probably will but that doesn’t mean supplementing is necessary in all cases. There are a variety of ways to get supplemental CO2 into your aquarium, and I will highlight the two we sell that I am now personally using. The CO2 Pro System by Red Sea, and the smaller Fluval Pressurized CO2 kit.
If the plants you have chosen are the type which either absolutely need CO2 supplementation (Dwarf Baby Tears Hemianthus callitrichoides) or will do much better with CO2 supplementation (Chain Sword Echinodorus tenellus) then these two systems will cover a range of aquariums from 10 to 200 gallons. I am using the Fluval system on a 40 gallon aquarium, and I am using the Red Sea system on a 265 gallon aquarium. The Fluval setup is using the 88g canisters manufactured by Fluval, and the Red Sea system is using a much larger tank of CO2 which we have rented from our local bottled gas/welding supplier.
Set Up and gas consumption: Both systems are very simple to set up, even for first timers. The Red Sea kit comes in two versions, one for use with paintball canisters and one for use with the larger bottle like I am using. The Fluval kit includes CO2 but the Red Sea kit does not, so keep this in mind. I have often been asked how long the 88g bottle on the Fluval CO2 kit lasts, and while it is not an exact science, I have used four bottles now and each one has lasted between 24 and 30 days depending on how I have the gas flow set and if I turn it off at night or not. The larger bottle on the Red Sea kit has been running two months, and it isn’t even half depleted yet so I would ballpark the larger tanks for the Red Sea kit to give about 4 months of service before needing to be refilled.