How much GFO to add

My boyfriend has some GFO in a filterbag in the overflow. The tank is 40 gallons, and he has had 2.5 tbsp's in there for over a month. I need to get rid of this algae. How much should I add to the reactor?

Also, any advice about ROX carbon? I was just going to add half what the calculator said.

 

Full dose is 10 grams or 4 level tablespoons for 40 gallons. It is wise in the beginning to cut that in half and change it more frequently so you don't shock stony corals so I would stick with the 2+/- spoonfulls.

 

Also - whats a better sponge that ROX carbon cannot get through?

 

Your flow should not be so high it lifts the carbon, its soft just like the GFO so requires lower flows so it doesn't grind itself to dust.

 

The website says to use a reactor capable of small particle media. The sponge that came with the BRS reactor is not.

 

In my mind what

means as much as anything is one with low flows so it does not carry the media out or grind it up. If the mediahas been rinsed well and the flows are correct the sponge really doesn't matter. If the media is rising up and fouling the sponge its probably been used too long, contains detritus and is exhausted anyway. I know if I am lazy on replacing the gfo or carbon in my two reactors it starts to clump and rise to the top, usually because it contains lots of organic material and is shot.

 

+1. I run Rox 0.8 in a Phosban reactor, which has a more porous sponge than the BRS. I have no problem with it coming through the sponge. I have a BRS reactor running GFO (smaller than Rox 0.8) and again have no problem with it escaping the sponge. The key is a slow tumble flow. Your GFO or Carbon should not rise through the reactor tube.