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.

[mike31154]

Depending on micron value, sediment filters are pretty much the same no matter where you get them. Carbon filters are a whole 'nother ball game, the quality & micron size can mean a big difference in what gets fed to your membrane, although the membrane & DI media should take care of most of the nasties. You're still getting a 0 TDS reading, so there may be something else going on. My carbon filter is 0.5 micron. Don't recall exactly when I replaced it, but I do recall checking the specs on the original & it was also 0.5 micron and rated to process something in the order of 20,000 gallons of water. Not sure RONA carries those, you should check the packaging to see what you got. It will probably be fine, but may need replacement sooner if it's a less efficient filter.