California Crow,
Thanks for sharing your success with AlgaeFix Marine regarding your algae problem.
The red (purple) cyano can be a real problem. Many hobbyists have used Erythromycin with some success. Many have reported that it returns after treatment (Randy has experienced this). Perhaps the treatment process with the antibiotics may need to be made for longer periods of time to completely eradicate it. Other than that, most who stay on top of it eventually win. I have some myself and I don't believe that the AlgaeFix is going to take care of it.