Cheap Aquarium CO2 Setup
When I first thought about adding CO2 to my planted aquarium, it was difficult to find a list of hardware needed to get things up and running.
This list is a fairly inexpensive way to get started with Co2 in your aquarium.
Hardware used for my first CO2 rig for my 75 gallon freshwater aquarium:
- 10lb CO2 tank from Craig’s List (with CO2 in it!) ($20)
- Aquarium CO2 Regulator with Solenoid 110V-Mini Dual Gauge Display Bubble Counter and Check Valve that Fits Standard US Tanks
- My original diffuser (https://smile.amazon.com/gp/product/B074MKPS23) is no longer available, but this seems to be the equivalent Twin Star CO2 Diffuser (Large)
- I wanted a mechanical timer for the solenoid (so my fish don’t suffocate at night) and went with this one: BN-LINK BND-60/U47 Indoor Mini 24-Hour Mechanical Outlet Timer, 3-Prong, 2-Pack
A drop checker is optional, but I went with this one: Glass Co2 Drop Checker with 4dkh/PH Solution
- A powerhead placed behind the diffuser really gets those CO2 bubbles moving around the tank and this is an equivalent to the one I used: Odyssea EX 250 DX Internal Powerhead
- Airline tubing. I used regular aquarium tubing for this and have not noticed any issues.
A drop checker is optional, but I went with this one: 
The biggest problem with this setup is that the bubble counter attached to the regulator dries out quickly. Not a huge deal as the diffuser can also be used to track bubbles.
Other than that, this setup has been running well for me for over a year.
That’s the list! I am not a CO2 expert, but will do my best to answer questions that you might have 🙂
Edit: After about a year of this setup, I’ve simplified it a bit, by removing the powerhead and placing the diffuser under the intake of my Fluval FX6 Canister Filter.
It’s one less thing to plug in and the drop-checker still looks the correct color.