CO2 injections?

Apr 27, 2015
Hey guys, I just got a 38 gallon tank with plans of adding plants into it, and putting my fish from a 10 gallon tank into this new one.
I have never had live plants before, and have heard about CO2 injections so the plants will grow. Our tap water (non-chlorinated) is full of CO2, so could i just use some of that, or are CO2 injections necessary?


Forum Manager
May 16, 2003
Hello, hopefully someone else will pipe up as I am not well versed in keeping aquarium plants, but from what I understand a CO2 injector is not 100% necessary, but can be helpful, especially if you get more serious into a planted tank. When you start adding CO2, you start messing with the chemistry of the tank and have to be ready to adjust as necessary and learn about kh and gh. Most people I know start a planted tank with a good substrate that plants will like, and make sure their lighting is sufficient.

It wouldn't hurt to do some more research into the type of plants you are trying to grow. Some require more specific conditions to thrive, while others don't need as much light or other conditions.


Elite Fish
Jul 19, 2004
Cape Cod
CO2 is only necessary for some specific more difficult plants, or if you have a heavily planted tank with high light (so that the plants are using up more CO2 than the fish are producing).

You don't need CO2 for most planted tanks. Plus you have to be careful with it as if you have too much going in, you can actually gas your fish.


Superstar Fish
Jan 11, 2013
East Aurora, NY
Like said, CO2 addition isn't necessary for a lower-light setup. As the intensity of the lighting goes up, so does the need for CO2. High light and not enough CO2 will eventually lead to an algae problem in your tank. It's all about the balance.

Glutaral products like Seachem's Flourish Excel, API liquid CO2, or commercially available Metricide 50 can be added as a CO2 substitute. It's not as efficient as real CO2, but has proven to work perfectly by more planted tank keepers than I care to link to.

Having a true planted tank takes lots of patience and resources. Often more than the fish require.

I used to be more diligent with glutaral and liquid fert additions to my tanks, but kind of stopped since I wasn't getting any more of a positive result than leaving it alone and just doing my weekly water changes. Here's my two 'tanks with plants'. I wouldn't really call them "planted'. The 29g contents used to be packed in a 10g. You really need a 20L at a minimum for a tank with plants.