Tips on keeping GFO in reactor.

[TWYOUNG]

I find gfo to be very "dusty" and difficult to rinse before placing in a reactor. Putting filter media around it leads to clogging and using nothing allows it to escape the reactor. I'm using a dual reactor and the gfo clogs the second carbon one. Does anyone have any advice or do you not worry about it getting in the tank? My sicce syncra is currently only able to push 6 gph through this.

 

[KrisReef]

I started rinsing gfo in a 5 gallon bucket before I used it to remove the fines. I would dump in a jar full and rinse until it was clean and then fill the filter. Excess washed gfo went back into the jar it came in and was ready for the next refill.

I stopped using gfo because I didn’t have good control over how much phosphate it would remove and switched to a liquid product.

Hth.

 

[jda]

You are going to have better results if you use the GFO and GAC separately. It is too hard to them together, IMO.

If you do use the GFO in it's own reactor, make sure that it is reverse flow and turn the pump up just enough so that the GFO tumbles just a bit - not too much. Then, just have the output into a bucket until the water is clean - this can be like .5 to 1 gallon. Then, run it in the tank. After a day, you can turn the pump up a bit and tumble the GFO a bit more. After another day or two, the GFO will likely be exhausted.

I find that an external reactor is easier for GFO since they are smaller and have tubes that you can move around to direct water into a bucket and then into the tank. Also, you need a ball valve on the pump. Phosban, AquaMax and many others work great.

GFO can unbind po4 if the tank water level gets lower, so always change it during a water change.

 

[TWYOUNG]

You are going to have better results if you use the GFO and GAC separately. It is too hard to them together, IMO.

If you do use the GFO in it's own reactor, make sure that it is reverse flow and turn the pump up just enough so that the GFO tumbles just a bit - not too much. Then, just have the output into a bucket until the water is clean - this can be like .5 to 1 gallon. Then, run it in the tank. After a day, you can turn the pump up a bit and tumble the GFO a bit more. After another day or two, the GFO will likely be exhausted.

I find that an external reactor is easier for GFO since they are smaller and have tubes that you can move around to direct water into a bucket and then into the tank. Also, you need a ball valve on the pump. Phosban, AquaMax and many others work great.

GFO can unbind po4 if the tank water level gets lower, so always change it during a water change.

Thanks, the gfo is in a separate reactor from the carbon but it's a dual reactor and they run in series. There is a valve so I can adjust it to tumble but that valve is wide open. I have the carbon packed between sponges to keep it from tumbling as that wouldn't be good for my tangs. It's been a couple of weeks since I changed carbon so cleaning that reactor would likely increase flow. I am getting movement of the gfo so do you think it matters if it's only got 6 gph of flow? Tank is 135 gals and I don't have a great deal of phosphate to remove.

 

[TWYOUNG]

I started rinsing gfo in a 5 gallon bucket before I used it to remove the fines. I would dump in a jar full and rinse until it was clean and then fill the filter. Excess washed gfo went back into the jar it came in and was ready for the next refill.

I stopped using gfo because I didn’t have good control over how much phosphate it would remove and switched to a liquid product.

Hth.

I'm new to gfo and it looked SO fine I didn't think it would settle in a bucket. If it did eventually settle it seemed it would likely be hard to get out. Do you let the "extra" dry before it goes back in the jar?

 

[KrisReef]

I'm new to gfo and it looked SO fine I didn't think it would settle in a bucket. If it did eventually settle it seemed it would likely be hard to get out. Do you let the "extra" dry before it goes back in the jar?

Nope, I put it back damp.

 

[jda]

I have no idea what GPH is right. It would likely depend on the width of the reactor and amount of media. If the GFO is gently tumbling, then it is likely OK.

You can test the output from reactors. When the po4 going in is the same as the exit, then the GFO is exhausted - likely a few days max.

Just keep in mind about getting a dedicated reactor down the road once you get sick of this. It can really help. I wish that nobody sold dual reactors since I cannot think of a single case where two different types of media had the same flow rates and exhausted at the same time... the people who sell them should know better. I guess that if you needed 2x GAC they might be OK.

 

[Randy Holmes-Farley Verified Community Expert]

I kept my GFO mixed with ROX 0.9 GAC in my BRS reactor just by the foam plug on top.

 

[TWYOUNG]

I kept my GFO mixed with ROX 0.9 GAC in my BRS reactor just by the foam plug on top.

I've heard concerns about mixing them as most say GFO will be exhausted long before carbon.

 

[TWYOUNG]

I have no idea what GPH is right. It would likely depend on the width of the reactor and amount of media. If the GFO is gently tumbling, then it is likely OK.

You can test the output from reactors. When the po4 going in is the same as the exit, then the GFO is exhausted - likely a few days max.

Just keep in mind about getting a dedicated reactor down the road once you get sick of this. It can really help. I wish that nobody sold dual reactors since I cannot think of a single case where two different types of media had the same flow rates and exhausted at the same time... the people who sell them should know better. I guess that if you needed 2x GAC they might be OK.

I agree the flow rates cannot be individualized but either media can be replaced at any time without disturbing the other.

 

[Floyd-]

When I ran a dual reactor I always setup to run through the carbon first then the GFO. Carbon should not tumble but GFO should tumble gently.

 

[Randy Holmes-Farley Verified Community Expert]

On the tumbling issue, that is just to allow water to contact all of the GFO without a big glob not getting water contact inside.

But if the GFO is dispersed among larger GAC, then it will get contact and I do not think tumbling is necessary or useful.

 

[TWYOUNG]

When I ran a dual reactor I always setup to run through the carbon first then the GFO. Carbon should not tumble but GFO should tumble gently.

I'm doing the reverse. GFO first so I can set the flow for optimum tumbling and carbon second. Since I don't want the carbon moving and grinding on itself I pack it tightly between sponges. I feel the sponges help trap any loose carbon, or GFO before it can escape the reactors.

 

[TWYOUNG]

On the tumbling issue, that is just to allow water to contact all of the GFO without a big glob not getting water contact inside.

But if the GFO is dispersed among larger GAC, then it will get contact and I do not think tumbling is necessary or useful.

Someone told me the GFO would "solidify" if not tumbled. I'm guessing that's not true? Do you recommend mixing GAC and GFO? Obviously this eliminates the ability to swap them out individually and most seem to feel GAC lasts much longer.

 

[Randy Holmes-Farley Verified Community Expert]

Someone told me the GFO would "solidify" if not tumbled. I'm guessing that's not true? Do you recommend mixing GAC and GFO? Obviously this eliminates the ability to swap them out individually and most seem to feel GAC lasts much longer.

If it is spaced out by GAC, that seems similar to tumbling and I did not notice any problems. GAC may last longer, but that depends on how much of what you use, and what the water phosphate level is.

 

[Saltyanimals]

I kept my GFO mixed with ROX 0.9 GAC in my BRS reactor just by the foam plug on top.

Hey @Randy Holmes-Farley I noticed you said using foam only on top. Do you fill/pack in the GFO/GAC mix to max?

One of the draw backs of the mix is that the collision of the 2 products will break up the granulates hence either packing or using the 2 foams. I've hit the max on a mini reactor forcing exhaustion in less than a week on a 180G. Next refill in 4-5 days I'm going to move to a full size BRS reactor and will mix the two to see how much longer I can go on a refill. The mini knocks down my PO4 about 0.1 at best before I have to refill which tells me I'm undersized for my tank and PO4 levels sitting around 0.2-0.3.

All tanks vary. .Curious how often you refill your full size BRS, PO4 levels and your system size? Thanks!

 

[Randy Holmes-Farley Verified Community Expert]

Hey @Randy Holmes-Farley I noticed you said using foam only on top. Do you fill/pack in the GFO/GAC mix to max?

One of the draw backs of the mix is that the collision of the 2 products will break up the granulates hence either packing or using the 2 foams. I've hit the max on a mini reactor forcing exhaustion in less than a week on a 180G. Next refill in 4-5 days I'm going to move to a full size BRS reactor and will mix the two to see how much longer I can go on a refill. The mini knocks down my PO4 about 0.1 at best before I have to refill which tells me I'm undersized for my tank and PO4 levels sitting around 0.2-0.3.

All tanks vary. .Curious how often you refill your full size BRS, PO4 levels and your system size? Thanks!

I would not design it so the solids are moving about. Lower flow or packed tight are alternatives.

 

[kilnakorr]

I found some GFO that has a much larger size grains. Easy to tumble in the reactor.
It doesn't work as fast as the fine GFO like rowaphos but lasts longer.
Maybe something like this is available in the US?

 

[Randy Holmes-Farley Verified Community Expert]

I found some GFO that has a much larger size grains. Easy to tumble in the reactor.
It doesn't work as fast as the fine GFO like rowaphos but lasts longer.
Maybe something like this is available in the US?

What brand and what size does it appear to be?

 

[X-37B]

I use old chemipure bags. I can put po4 media in one bag and carbon in another. Easy to rinse and both can go in the reactor together. I have done this for years when both are needed.
Simple and works well.