Carbonic Service on De La Cruz (San Jose/Santa Clara) refills while you wait (10 minutes). You can also buy CO2 tanks from them. Filled 10# tank was around $80. If you're just refilling cost is less than $10 (think it was $8 for filling).
I also go to Carbonic services in Santa Clara. Refill for #10 has increased to about $12, still not bad. The wait is more like 5 minutes
Truvu 100g Flourite, wet/dry, AHSupply 302w PC, PinPoint controller 10gallon15w T6+15w T8 55gallon40w T6 ODNO4x, no CO2. Discus grow out.
10gallon Tonina tank, 2x15w T6 ODNO 4x
I will do aquascapes after I collect all the plant species and grow them to perfection.
Look for a home beer brewing store near you. There is one in Concord near the Costco. I can't remember its name as i just drop by when I need more CO2. They will swap out empty tanks for full ones at a rasonable cost. Good luck.