I got this in January to try and it worked fine for a few months before going crazy on me today which is about exactly 3 months later.
My CO2 starts at around 1600 before lights on at 1700. I went up to take a look at my tank at 1845. Almost every fish and shrimp was either dead or unconscious!!! Damned needle valve had slipped and the bubble rate was crazy!
Considering that my cylinder's a 8kg which still hasn't shown any signs of a pressure drop despite 3 months of fast bubble rates, had I gone on holiday, even the plants could have been gassed to death!
This is how the ads look like.