I tried a few different low cost CO2 setups, the Fluval mini CO2 system, as well as a 20gram cartridge with a diffuser. I wasn't able to get consistent results as the pressure in the cartridge is always decreasing, so you need to adjust the valve daily or twice daily.
Perhaps the CO2 reactors using a time release gel, like from Dennerle, could be better, but you end up needing to purchase new gel and yeast monthly, it actually becomes more expensive than a pro system.
I now run a 5lb CO2 tank, dual STAGE regulator from ebay, and a solenoid that I run off a Wemo Mini SmartPlug which I can program to turn on and off twice a day for my tank siesta period. I also run an EHEIM 350 surface skimmer off a separate Wemo mini smart plug, so that it runs once or twice a day for 10 minutes, and "on-demand" anytime, but with a 10 minute auto-off.
Really nice devices, the Wemo mini smart plugs, and only about $17 each. "Hey Siri, turn on skimmer"..... boom.