What i did was got the regulator from aquaristic, then got a 2kg co2 fire extinguisher off ebay for about £15 inc p+p, removed the hose, attached the reg with plenty of plumbers tape then cable tied the fire extinguisher handle down - works great. But...... i am just saying this is what i did, I’m not saying anyone else should do it, and I’m saying it's necessarily big or clever – this approach does seen quite popular with the reef people and their calcium reactors though.

neil