I have been struggling with cyanobacteria in one of my tanks, it probably started due to increased bioload when my Cichlasomas bred, until I removed them at 2-3 cm there were 42 babies plus the parents, three Apistogrammas and 4 otos. The tank is 240 litres (about 63 gallons). The BGA started on the roots of the floating plants, which I removed the affected ones regularly, but it then spread to the driftwood, rocks, substrate and was starting to affect the plants that had already been hammered by the activities of the cichlids. I tried to keep it under control, removing, scrubbing, siphoning and cleaning or removing affected plants. I cut down the light hours and did more frequent and bigger water changes, but it just kept growing back. I did not want to do a blackout as it would probablyy kill the otos’ food as well, and I did not want to use antibiotics even if I could get hold of them. I had considered trying excel, but not tried it yet. After a mammoth cleaning session last Saturday, by Monday more BGA was back, I cleaned and siphoned again, by Tuesday it was all over the substrate again. Then I had the idea of using almond leaves. After all they are supposed to have antibacterial properties. I googled it and found a couple of references to suggest that they might help, but nothing concrete. So after another cleaning session on Tuesday I added 3 large leaves, enough to slightly tint the water. The BGA has not come back yet! And today I just did a regular water change. Of course I cant be 100% sure the leaves have helped, maybe a combination of everything else I was doing but the difference was impressive and immediate. I wanted to report this as it may be a good solution at least for mild cases. I will post an update next week.