https://www.newscientist.com/article/2095799-bacteria-gardeners-farm-algae-to-harvest-when-food-runs-out/
Here's an interesting article describing how certain species of bacteria farm algae. The algae produces nutrients and in return, the bacteria produces antibiotics which protects the algae from other bacteria.
Regarding GDA, Tom Barr mentioned that he's been able to get rid of GDA after adding erythromycin, an antibiotic which kills certain types of bacteria. He didn't know why since it has no direct effect on algae but I suspect that it's because the bacteria was killed off that had a symbiotic relationship with the algae. If the algae could only survive in the presence of the bacteria, then no bacteria meant no GDA.
Here's an interesting article describing how certain species of bacteria farm algae. The algae produces nutrients and in return, the bacteria produces antibiotics which protects the algae from other bacteria.
Regarding GDA, Tom Barr mentioned that he's been able to get rid of GDA after adding erythromycin, an antibiotic which kills certain types of bacteria. He didn't know why since it has no direct effect on algae but I suspect that it's because the bacteria was killed off that had a symbiotic relationship with the algae. If the algae could only survive in the presence of the bacteria, then no bacteria meant no GDA.