I have been battling cyano for a while now. i have done multiple treatments with chemi-clean and it keeps coming back, or never really goes away. I have just added a u/v light to see if that helps. not sure what else to do. it is a 40g tank with a 10g refugium that is flourishing. my make up water is ro/di @ 0 ppm nitrates and phosphates are both @ 0 via Salifert test kits.
IMAG0800_zps7p87bi2y.jpg Photo by desertranger1 | Photobucket
IMAG0800_zps7p87bi2y.jpg Photo by desertranger1 | Photobucket