DevUK
UKAPS member
to make the kit cheaper, you can cancel out the solenoid and run the CO2 24/7. This means you will only get about 3months out of a 2kg though.
without a solenoid a reg costs £30
Thanks for the info Steve
£30 if you're lucky like I was - I snarfed an Aqua Medic reg for that including shipping
I think budgeting £50 for a reg would be the safest bet, incase one can't be found for less. Lunapet regs are good. I bought one of these for my first regulator and still use it. Lunapet also do solenoids quite cheap too. About £22 with shipping from Germany which is far cheaper than most places that I've seen.
Running the CO2 24/7 means you might get away with slightly less bubbles per min (it's totally dependant on your own setup though, can't really compare to someone elses too easily due to all the different factors - plant mass, growth rates, light levels etc etc). But yeah, 3 or 4 months hopefully.