Join Date: Jun 2012
Location: Gainesville, FL
CO2 levels are certainly not the only factor involved with BBA. The same could be said for the cause of traffic accidents when the driver was intoxicated. CO2 has been around for millions of years. Simply because it's injected or not does not eliminate it as a factor for BBA. A weekly water change, turning the lights on/off, decreasing flow from dirty filters, pruning or adding plants, poor water circulation, and many more can all cause CO2 changes.
Now that we use CO2 it's no wonder BBA has become worse. Now in addition to the other causes we have changes as a result of cheap regulators, turning it on/off, poor diffusion, and worse yet bad DIY CO2 setups to name a few.
BBA grows naturally in fast flowing streams and rivers where CO2 is high and fluctuating. Ever floated down one of the spring fed rivers in Florida? It's everywhere. I certainly don't have all the answers but I've noticed that most of the time a condition for fluctuating CO2 levels was present when a hobbyist had a problem with it. Correcting that problem seemed to alleviate the BBA. Why do CO2 levels trigger it? I have no idea. But if we look at where is grows naturally we see the same issue. Everything seems to have a niche in nature. When we create a similar niche in our tanks it's bound to be a problem.