Cyano problem, should I use GFO? How to best use GFO?


New member
I have a 46 gallon Bowfront with a cyano problem, and to a lesser extent some hair algae. I have been running a protein skimmer (reef octopus rated for 150 gallons and have a good sized refugium with Chaeto - lights on at night only. One week ago I took all the liverock out, cleaned them and put in a deep sand bed (dead sand). I know I have made a lot of changes recently and maybe I just need to be patient, but should I add a GFO reactor? If so, how much GFO for my system? How often should I replace the media? I have heard that GFO can have some deleterious effects? Any help would be appreciated.


New member
I recommend a smaller then needed skimmer. Coral and critters like a little waste. Even use it 2 weeks a month according to water readings and maintance.
Do you have any powerheads?
Whats your phosphate reading?

You dont need any fancy equipment to run a smaller tank. The basics is all i ever use in 75 gallon for 10 years. Water source , rock , sand , HOB filter and good water flow. I dont even use a skimmer. But i only have 4 fish. It all about the coral. Always the same reaction from friends "Thats So Cool" talking about the coral. Anybody can have fish, but corals , i mean having an actual mini reef in my sitting room still blows me away. Its a gift you should not abuse. NO CRACK HEADS IN REEFING. Sorry im on number 12.

Bud Light>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>And listing to chevell. YEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA


New member
How much substrate did you add? What kind? What did you do to your rock to "clean" them? What are your parameters, and what do you use to test them? Are you using an RO/DI unit?


Team RC
I would not run GFO without a reason, but if you do have issues with phosphates (almost all of us) GFO is great. Check out BRS, they have a good video that shows you how to set up a GFO reactor. BRS also has a calculator so you know how much GFO and or Carbon to run in your system. Initially if your phosphates are high you may need to change it out weekly, but after you get it under control you can stretch it out to once every three weeks.