How Long Does Your GFO Typically Last?

[PeterC99]

Just installed a BRS dual stage reactor with GFO and carbon.

PO4 went from .21 to .05 with reactor running 4 hours/day in just 3 days. Sweet! Have dialed back reactor time to only turn on for 2 hours a day.

What is the typical useful life of GFO and when do you replace it?

 

[Tidal Gardens Verified Sponsor]

We have found that it can last quite a while if done correctly and you have it dialed in just right. On that note, it can remove way more phosphate than you think and we suggest going SLOW. That drastic drop might not have been the best thing.

 

[PeterC99]

Appreciate the response!

So what is the preferred way to go slow?

1) Fill Reactor 1/4 way with GFO and run 24/7

or

2) Fill Reactor 100% and run one or 2 hours a day?

 

[LAX Noob Reef]

Either get a super slow pump, or get a vale control and turn it to 10-20% only. Why? Because GFO/ Carb might lead to dino which is way worst then what you have right now.

 

[PeterC99]

Have both slow pump and value control. Only running pump 2 hours/day now.

 

[fcmatt]

In my cannister for my 70 gal tank I use gfo in terms of tablespoons full. Like 2 to 3 tablespoons. The stuff is ridiculously powerful and less is more if you follow me. It can harm a tank. I switch it out every 2 to 3 weeks. It is basically there to just help combat phosphate a bit and not really control it. Uneaten food, fish poop, etc.. the skimmer and occasional filter sock miss.

Since I use so little each time and I rarely test anymore I don't care how long it lasts. It is cheap. I add with my carbon in the same cannister off my manifold.

 

[PeterC99]

Interesting that my LFS store sold me the setup Prefilled with GFO and Carbon. Setup did come with pump and control value. He told me run a few hours a day with control value about 1/2 way. Have since dialed back control value to 1/4 open and only run one hour a day ( but may take that down to 1/2 hour)

Seeing first hand how powerful the GFO is.

Question - Is it better to run small amount of GFO 24/7 or full canister short time? Or does it not make any difference?

 

[Reefvision]

I suggest testing as a good way to keep phos at the level you want. The test results will tell when it’s exhausted and needs changing. This will become less tedious after awhile and testing will not be as frequent. As others have stated GO SLOW!!

 

[BobT]

In my 90 I use 1/4 cup in reactor running 24/7 which last about 3 weeks. I replace when phosphate levels rise (testing weekly).

 

[schooncw]

I use GFO but am thinking of trying out Lanthanum Chloride

 

[schuby]

I've tried the stop and start method, but my reactor gets clogged more easily. Running less GFO at a constant rate ( GFO waving and not flying around) reduces clogging significantly.

I'd recommend testing PO4 frequently when you first start GFO so you understand its effect. Don't let PO4 (or Nitrate) stay at zero: bad things follow.

 

[Reefvision]

I used to use a reactor for a year I guess but it was just a pita to clean and replace the media, so I just swap out filled media bags that are in sump chamber now . Doesn’t tumble as recommended but still works for me.change around 3 weeks or so.

 

[WVNed]

1500ml in a reactor
2 weeks

 

[homer1475]

I use very, very little on my 80G.

I like to maintain my levels and have found that 2 tablespoons mixed in with my carbon in a reverse flow reactor(water pushed down through media, as opposed to up through), lasts about a week to 2 weeks, and maintains my levels right around .15.

If my levels drop lower, I discountinue use for a couple weeks, then throw it back in when they start to raise.

 

[Bpb]

2 cups of high capacity gfo in my 150 gallon has lasted about 2-3 weeks. Po4 is creeping back up. Odd how some of y’all can use 1-2 tablespoons and that’s enough.