I have this exact CO2 setup on my 20g. It works perfectly fine. I did replace the diffuser ladder with a glass diffuser. The glass diffuser produces finer bubbles. In reality, you are paying for a very sturdy heavy plastic container and proper CO2 tubing. I do not use the packets but instead mix my own yeast - baking soda - sugar - water mixture. It does not last for three months. Closer to one week, sometimes two. I am not interested too much in DIY projects so this was perfect for my modest set up.