RO Water - Causing Cyano?

[Coralgurl]

I recently changed my filters on my RO unit and finally clued in the timing of the change and appearance of cyano seems to run hand in hand. I replaced the sediment filter with the same brand as previous, however my carbon filter is slightly different. Purchased both from RONA. My TDS meter reads 0. I use a dual reactor running HC GFO and carbon and lately have cut back on the fish feedings. Filter socks changed every few days and skimmer running fine.

No I haven't tested as its obvious something is going on, the only thing I can think of is my water. Any ideas?

I am a week overdue for a water change, but I need to buy a new Brute can as my heater burnt a hole in the side of the one I use for SW and its not repairable.