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Aquarium CO2

Aquarium CO2 System - which one should I choose?

Aquarium CO2 System - which one should I choose?

Nothing boosts the growth of our aquatic plants as much as the CO2 gas in the aquarium. To do this, you need a carbon dioxide system. The following article explains the different types of CO2 systems and helps to choose the right one for your needs.

CO2 systems with yeast

These are the cheapest and simplest CO2 systems on the market. You can build one at home with some DIY skills, but because of the relatively low prices, it is also worth considering the off-the-shelf products.
If you like to DIY, here is the "recipe" for a carbon dioxide system that you can make at home:
You don't need anything else, only a 1.5-liter pet bottle, a little sugar, yeast, and lukewarm water. Drill the cap so an aquarium aeration pipe fits inside. Pour two dl of sugar into the glass, then a teaspoon of yeast. Pour this with 1 liter of lukewarm water and shake well. Close the bottle with the cap and wait patiently. Fermentation starts within a few hours, and CO2 runs through the pipe. The gas then needs to be delivered to the aquarium water with the help of a CO2 diffuser. This basic system is suitable for testing and experiencing what happens to our plants when they get some extra CO2. But it is, unfortunately, fiddly to operate in the long term since the bottle only works for 1-2 weeks.

The gel/yeast systems, which you can find now with many aquarium manufacturers, work for 30-50 days with one mixed solution. By slowing down the fermentation, the jelly evens out the formation of CO2 gas, thus providing a more effective and longer-term solution than the basic yeast one. The products are affordable and fit in small spaces. Still, you can't change the CO2 diffusion intensity/rate, so these systems are only used for aquariums under 50 liters. If you want to experience the effects of CO2 gas on your plants in a small aquarium but don't want to spend a considerable amount of money, it can be a perfect way to try it.

Disposable and small bottle CO2 systems

They are a bit more expensive, but they already bring significant advantages with the high pressure. With these systems, the CO2 intensity can be changed, and they can operate much longer with one charge than gel or yeast systems.

Tropica's small bottle system is similar to traditional soda machines' "roll-on" cartridges. There is 90g of carbon dioxide gas in a bottle, which can be precisely adjusted and dosed into our aquarium through a small CO2 regulator. Its advantage is the compact form factor and price, but the higher cost of replacement bottles can be pretty expensive to operate in the long term.

The Dennerle Carbo Soda is relatively new on the aquarium CO2 system market and is compatible with the well-known SodaStream bottles. It provides an excellent alternative for those who do not have a gas exchange/refiller station nearby for large CO2 cylinders but have access to the SodaStream bottle replacement places. 

Dennerle Carbo Soda CO2 system

Pressurized CO2 systems

These systems are for those who want a permanent and precise CO2 system. They usually work with 2kg, 5kg, 10kg, or larger bottles. With the larger bottle size, you need more space in the cabinet. The CO2 regulators on these systems are compatible with a solenoid valve. This way, they can be switched on and off with a timer and fully automated with a pH sensor later if you wish. Of course, these are much more expensive than the simpler CO2 systems described above, but they work economically in the long term without maintenance.

Pressurized CO2 system parts
If you do not have access to a place nearby where you can refill or replace large CO2 bottles, a SodaStream adapter is available for the CO2 regulator. With this adapter, you can use the regulator with SodaStream bottles available in many places.

We hope this article helps you navigate through the available CO2 systems and that you find the ideal solution for your aquarium.

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