running carbon and gfo?

[ffsteve]

hi everyone, i have been running plain carbon in my 180g. just the sac kind in my filter socks. i want to upgrage to a dual chamber reactor for carbon and gfo.
first what is gfo? i know it's for algae, but what does gfo stand for?

second how long should i run the carbon for? 24/7
and how long should i run the gfo for? 24/7 also?

and lastly how do you know when your carbon and the gfo is used up?

thanks steve

 

[gweston]

GFO = granular ferric oxide. Basically it is chunks of 'rusted iron'. It removes phosphates from the water which algae feed on. Good skimming and periodic water changes can help keep phosphates in check, but adding GFO can help you keep it down even lower. As in near 0. I started using a little bit of it along with carbon in a filter sock for my 29gal. Phosphates are practically undetectable now and it certainly helped with algae growth. Obviously it doesn't eliminate it. Just keeps nuisance algae at bay.

I think most carbon can be run for around 4 weeks. GFO can be run for a few months. But I guess it depends on the brand/type and how you are running it. In my case with the filter sock. I mix mostly carbon with a little GFO in the same sock. It gets moderate flow and I change the whole thing out monthly. The GFO may not be entirely used up though. I'm going the dual reactor route myself once I get the big tank in place later this year. Right now for the 29gal/sump system, I'm keeping it simple.

 

[Jocko]

Just curious, what's your motivator here? Are you having a big problem with algae?

 

[ffsteve]

i always have alge problem lol. brown, red, maroon, you name it.