Red Cyano problem

[RPatsula]

Well it seems about three or four weeks ago I started to get a red cyano problem. It is basically all over my sand. And this morning two of my gobies decided to jump ship and I found them on the floor next to the aquarium.
Here is my tank configuration: two MP 40s, two MP 10s, four Radeon lights, 230 gallon display tank with about 120 pounds of live rock, hundred gallon sump, vertex 280 skimmer, RO/DI auto top off system, 45 gallon food grade water change unit, GFO/Carbon reactor.
My livestock is as follows: one yellow Tang, six chromis, one goby, approximately 30 crabs and 20 snails. I feed flakes once a day and I am pretty sure I'm not over feeding them.
I have been doing a 40 to 45 gallon water change every week for the past two months. My RODI unit is reading three right now so I think I will change my filters on it.
Whenever I test my water I get a zero reading for nitrates or phosphates and my pH is that 8.3 about and my salinity is 1.025. I keep my water at 79°F to 80°F.
I purchased some redcyano RX and currently trying to get rid of it this way. My first treatment, two days ago, seem to be unsuccessful so I am starting my second treatment today. I siphoned off as much as the red Cyano as I could off the sandbed. I have also turned off my GFO/Carbon reactor and protein skimmer well I am doing this treatment.
My aquarium setup is approximately 1-year-old and this is the first breakout I have had. Any suggestions would be greatly appreciate. This is very frustrating.

Rick