Calcium Reactor 100% or 5% CO2

[KevK]

Just picked up a Kr2 calcium reactor, price was very good and I really don't want to pressurize anything I build. Do these use 100% or 5% Co2. Is there a good place in the Chelmsford area to get a stubby and get it filled?

[pantinor]

I use the Merriam-Graves on route 110 in dracut, near lowell.

[KevK]

Thanks
Kevin