sure there always is. someone is selling a complete CO² system on the boards here for a good price. CO² is one of the best things you can do for your plants to make them grow bigger. The other is a good misting fogger for the vegetation cycle. It's amazing how fast and lush they can grow with a good fogger and humidity in the 70-80% range.

Not that that high of a range does not bring it's own set of problems that you need to manage but that's ok. it's worth the effort.