In 2017, I was given a SodaStream that carbonates water using a refillable 60 liter CO2 cylinder. The cost of a refill cylinder was a bit high, but I was only using four or five cylinders a year. in 2024, compatible CO2 cylinders like Indigo and Reflo became available at a lower price, and they would accept the empty SodaStream cylinders.
SodaStream
In 2017, I was given a SodaStream (https://sodastream.ca/) device that injects CO2 from a rechargeable cylinder into water. The injection rate dropped noticeably in the last few weeks, even with a full CO2 cylinder.