Is GFO necessary with a large regfugium?

[Herby’s reef]

I have always run GFO and had very good success with it. Recently I have been running a very large triton style refugium with the Kessil refugium light. I have 0 detectable nitrates or phosphates with this, and I recently stopped changing my GFO. I still have 0 detectable phosphates with a Hanna checker so my question is do I need the GFO to prevent algae outbreak. I know that I have phosphates because I still have to clean the glass, and my Cheato grows like crazy! I dont mind running the GFO, it almost makes me feel better because I have always done it, but I worry that running it in my already low phosphate environment may damage my coral or clams in some way. Is this a valid worry? I have a primarily LPS tank with a few sps and two clams. 170 gallon total volume tank. With heavy bioload and I feed frequently.

 

[Flexin]

See how your tank does without it if that's the direction you want to go. With mine, I don't run GFO but different tanks have different challenges. I read so many mixed reviews on having or not having nitrates. So I'm interested in the comments.

 

[Nburg's Reef]

Only run GFO if you have a phosphate problem. If your fuge keeps it in check, then adding GFO will only affect your fuge and cause your fuge to under perform. Don't feel you need it as a comfort blanket. In past SPS tanks, I actually saw better results when I discontinued use because I think it was tripping too much out of the water.

FWIW, I had a fuge that I took offline because it was keeping the water too clean. So now I just run a skimmer and a small media bag of GFO and GAC just to keep things in line. works for me, but I also have a small bioload and dose nitrates to the tank.

 

[XNavyDiver]

I have always run GFO and had very good success with it. Recently I have been running a very large triton style refugium with the Kessil refugium light. I have 0 detectable nitrates or phosphates with this, and I recently stopped changing my GFO. I still have 0 detectable phosphates with a Hanna checker so my question is do I need the GFO to prevent algae outbreak. I know that I have phosphates because I still have to clean the glass, and my Cheato grows like crazy! I dont mind running the GFO, it almost makes me feel better because I have always done it, but I worry that running it in my already low phosphate environment may damage my coral or clams in some way. Is this a valid worry? I have a primarily LPS tank with a few sps and two clams. 170 gallon total volume tank. With heavy bioload and I feed frequently.

If you have the ability to dial down the flow through your gfo reactor, I would slowly dial it down over some days, measure your po4 during this process until the flow is eventually zero. If your po4 rises during this process you can open the flow up a bit. Always the best indicator is your corals. They will usually tell you if they like or don't like the change you're making.

 

[Herby’s reef]

Only run GFO if you have a phosphate problem. If your fuge keeps it in check, then adding GFO will only affect your fuge and cause your fuge to under perform. Don't feel you need it as a comfort blanket. In past SPS tanks, I actually saw better results when I discontinued use because I think it was tripping too much out of the water.

FWIW, I had a fuge that I took offline because it was keeping the water too clean. So now I just run a skimmer and a small media bag of GFO and GAC just to keep things in line. works for me, but I also have a small bioload and dose nitrates to the tank.

Thanks! I was worried that I might cause problems with the fuge if I started running GFO again. I had GFO in the media reactors until today, but it was at least 3 months old so I assume it was exhausted. I will monitor my phosphates and corals closely over the next few days and see how it goes. I appreciate all the replies!

 

[Mal11224]

After my tank was running for 3 months I started GFO/GAC mix in my reactor and had problems with my corals bleaching and realized that I had to stop using GFO. I felt like it needed to be done but it was not necessary. I have a fuge in my sump and have never had Phosphate issues. I guess I was overdoing it at the time. Have not used it since. Tank is about 11 months old now and phosphates still read zero with Hanna. Corals started doing much better. Advice above is good. I would dial it down and measure daily to see if your phosphates do go up and ultimately discontinue the use. Let your fuge handle it.

 

[ChrisOFL]

I used to run GFO till I discovered my tank can process phosphates ridiculously well and have never used it since. I test phosphates maybe every 3 months and have yet to register above 0.00 and this is after a year. I feed very heavy but even with dosing phosphates it was impossible to detect them after 12hours. I stopped dosing because I saw no changes other than some small patches of hair algae popping up. If your tank can handle it on its own there is no point in adding something extra I feel like. You may even cause issues with running GFO with no detectable phosphates.

 

[cumbeje]

I measure my phosphates weekly with Hanna checker add or remove GFO based on keeping my numbers in the .01-04 range. If it gets too high I will add GFO or gets too low I remove it.