In answer to
John P Coates
I needed a new reg and got a lot for my money from CO2 Art who give excellent customer service. I didn't really expect it to be a 'proper' Dual stage reg at that price. All that matters is that i don't get EOTD, and I will avoid allowing the tank pressure to drop to low, so only time will tell. If i want a proper hairy balls Dual stage reg then I expect to pay a lot more than £50. I have a kind of fetish for the Custom/high end Dual stages for sale @Barr report Trades,swaps and sales but I just can't justify paying that much for a CO2 regulator to run one tank. If I had multiple planted tanks maybe.
Like my mum says, 'I've got champagne tastes but only beer money' and i do like the best kit.
It seems to me there is a lot of over information/myth surrounding CO2 problems put out there.
John S
The reg is similar in size/design to other single stage regs that are available/I've owned and I can't see there being two diaphragms in the CO2 Art reg. But I'm happy to be proved wrong by someone who knows more than I do (which ain't much) Either way I'm happy with the CO2 Art reg and the service I've received from them. And yes the working pressure is adjustable (blue dial on front of reg body) as well as fine adjustment with a needle valve.
It's possible that the best option is an electronic CO2 metering device, such as the 'Carbon Doser' from aquariumplants.com. You pays your money you makes your choice.