Help me implement GFO

[BigJohnny]

Hey Reefers,

I have always avoided using GFO in my reef tanks, but my phosphates recently climbed up to .26ppm and my nitrates are only 4ppm. I had a tank sitter excessively overfeed my tank and I have also been neglecting water changes since the birth of my first child.

I'm sure it will balance out on its own but I would like to help it along. I could do some large water changes, and i do have a small refugium, but in this instance I think the best way to handle this is to gradually reduce po4 with GFO since I like my nitrates where they are at (or higher). I know it's better in a reactor but I'd like to run it passively in a bag hanging in front of my skimmer output.

Tank is 90g DT with 40g sump, about 105g total water volume. I have some BRS high capacity GFO, how much do you think I should use? I obviously don't want to strip it too quickly.

Thanks!

 

[Scorpius]

I'd run 5 tablespoons of BRS HC gfo. I always go half on carbon/gfo recommendations.

 

[BigJohnny]

I'd run 5 tablespoons of BRS HC gfo. I always go half on carbon/gfo recommendations.

Ok, thanks. Do I have to rinse it like carbon?

 

[BigJohnny]

Ok, thanks. Do I have to rinse it like carbon?

Nvm, looked it up like a normal person. Does anyone here run it passively? Do I need to massage the bag (watch yo mouth) daily or anything?

 

[reeferfoxx]

Nvm, looked it up like a normal person. Does anyone here run it passively? Do I need to massage the bag (watch yo mouth) daily or anything?

No, as long as water flows through it, assuming its not packed tightly, you should be fine. Just monitor po4 daily till you reach a comfortable 0.03-0.08. Then remove the GFO. Then monitor po4 again. Doing this should allow you to see how quickly it raises and how often or intermittently you should implement GFO. But I would also look into a algae turf scrubber or cheato for long term nutrient control.

 

[BigJohnny]

No, as long as water flows through it, assuming its not packed tightly, you should be fine. Just monitor po4 daily till you reach a comfortable 0.03-0.08. Then remove the GFO. Then monitor po4 again. Doing this should allow you to see how quickly it raises and how often or intermittently you should implement GFO. But I would also look into a algae turf scrubber or cheato for long term nutrient control.

Thanks, I mean it's not packed unnaturally tight but it's all at the bottom of the bag. Have it hanging in front of my skimmer output. I actually prefer about .1ppm but yes I will monitor daily. This is due to an isolated incident so I should not have to run it again, thankfully. My skimmer/refugium/water change schedule keeps things in check normally. Thanks!