How often do you Replace GFO and Carbon?

[that Reef Guy]

How often do you Replace GFO and Carbon?

I was told by one person to change your Carbon once a month.

But then someone else said it does absolutely nothing after a week so you have to change it weekly.

And as for GFO I have no idea?

 

[robbrouse]

I mix mine in the same reactor and I change mine every 10 days. I mix 2 part carbon and 1 part GFO. Id never run carbon more than 10 days. That's just me. In my freshwater tank I do run carbon 2 weeks. Change it when I do the water change.

 

[AZDesertRat]

It really depends on your phosphate levels for GFO. You will start with a lower dose and change more often in the beginning then start to work upo to a full dose over time if you do not see the phosphates dropping using a good test kit. It could be weekly at first and monthly or 6 weeks once things are in check but the test kit will tell the story.

I go a couple weeks on carbon when I remember. I do not recommend mixing them in one bag or reactor as they have very different useful lives and different flow requirements to get the full use of them so you end up wasting one changing too often or stretching the other past its prime.

 

[robbrouse]

I do agree with the AZ said about not mixing them. It's just they way I went and have not added a second reactor. I know I'm wasting GFO.. I hope to get a 2nd reactor soon. Forgot to bring that up thanks AZ...

 

[Palting]

GFO is consumed as it adsorbs phosphates, So, keep your eye on your phosphates. If it starts trending up, replace your GFO. If phosphates are zero or still going down, keep it. Don't keep it for more than a month, though. You don't want your chemical media to get colonized and go biologic. My phosphates have always been 0 and have no algae issues thanks to a refugium with macroalage, so I quit using GFO.

There is no test to see if carbon needs changing. Truth be told, there are experts out there who say do not use carbon in a marine tank, but that's a whole 'nother discussion. Anyway, use 1 cup quality carbon for every 100 gallons system volume, and replace monthly.