I am new to keeping a planted aquarium although I have been keeping fish for many years. My plants are struggling and I read about CO2 supplementation. Everyone talks about counting the bubbles but I don't understand how many bubbles are appropriate. I have a 40 gallon planted tank. The miniature swords do very well, the regular Amazon swords get by. Most of the other plants do well for a while and then die off. Any input would be appreciated. I have read numerous reviews of the different CO2 systems but would like more guidance concerning how to control how much CO2 goes into the tank before I put my fish at risk.