<— NARROW YOUR SEARCH: We are considered the leader when it comes to C02 equipment… C02 injection in an aquarium need not be complicated or problematic when done correctly. If you have any questions, call us. We would rather help "before" you have problems.One of the biggest problems with C02 systems is the regulator. Most on the market are made in China and are very poorly built. Problems include very inconsistant "bubble counts" and very short life span. Most regulators on the market have only a 6 month warranty…Check out our exclusive: AquariumPlants.com's own "CarbonDoser® Electronic C02 Regulator“. 3 year warranty!!!