Phosphate Reactor help

[jroush00]

Hello I just received one of these in the mail and the pump was missing the flow adjustment. When I turn it on it pushes the phosphate remover together and tightly against the top filter pad. Does this stuff need to move or can it just stay like it is?

Thanks

Josh

 

[Fishguy2727]

It is fine. As long as it is getting flow it is fine.

 

[ccCapt]

What phosphate removing media are you using? GFO is supposed to gently tumble in a reactor.
Here's what mine looks like.
GFO - YouTube

 

[jroush00]

Yeah I thought it was supposed to. Guess I will have to wait for the manufacturer to send the part. Thanks for the help

 

[Fishguy2727]

How does tumbling increase phosphate removal versus higher flow that prevents tumbling?

 

[ccCapt]

I guess that's a question you should ask of every retailer that sells GFO and recommends it tumble gently in a reactor.

 

[Fishguy2727]

That is why I am asking here. I hear that all the time but I have never heard an explanation for it. As long as it is wet and getting flow it can do its job. Any actual facts to support it needs to gently tumble or are we all just regurgitating what the last guy said (myself included, so no disrespect)?

I don't think it needs the lower flow. I think that like carbon in a canister filter the higher flow will not reduce its effectiveness.

 

[carey]

I can only assume its for the best water contact with the media. I've watched all the videos and read everything I can on these and they all suggest a tumbling action.

 

[ccCapt]

That is why I am asking here. I hear that all the time but I have never heard an explanation for it. As long as it is wet and getting flow it can do its job. Any actual facts to support it needs to gently tumble or are we all just regurgitating what the last guy said (myself included, so no disrespect)?

I don't think it needs the lower flow. I think that like carbon in a canister filter the higher flow will not reduce its effectiveness.

Iron Oxide Hydroxide (GFO) Phosphate Binders by Randy Holmes-Farley - Reefkeeping.com
"Many aquarists use GFO in a fluidized bed reactor. This method reduces the likelihood of forming the particles into an unusable solid cake, although it does not always prevent this from happening. Some manufacturers sell reactors for this purpose. Some aquarists that have used the GFO in a traditional media bag report that it formed a brick in short order. Such caking may relate to calcium carbonate precipitation, or even to bacteria that are known to be able to knit the surfaces of two small iron oxide hydroxide particles together into a single particle."

 

[Fishguy2727]

I am curious about why it is different from carbon. Carbon does best with the most flow. So far the only fact is 'everyone says so' with no scientific or factual support.

This would be a good situation for an experiment. Setup 500g of tumbling GFO in a reactor and see: how long it takes to be exhausted (exhausted defined as phosphate no longer undetectable in the output water) and the effect on the main water column. Compare this to 500g of GFO in a reactor with a much higher flow rate and compare the two. I think that the higher flow will be more effective. Either way you should get undetectable phosphate in the output water, the difference will be how long it takes to become exhausted, sooner meaning the method is more effective (the same amount of GFO exhausted sooner means it removed the same amount of phosphate in a shorter amount of time). Or they last the same amount of time but the impact on the phosphate concentration on the water column is different.

Even if the higher flow rate doesn't produce an undetectable phosphate concentration in the output water it could still be more effective. I think lower flow may get a lower concentration in the output water, but will not be as effective on the concentration in the water column, which is more important.

If anyone wants to set this up that would be amazing (should be very easy for anyone running GFO).

 

[Fishguy2727]

Iron Oxide Hydroxide (GFO) Phosphate Binders by Randy Holmes-Farley - Reefkeeping.com
"Many aquarists use GFO in a fluidized bed reactor. This method reduces the likelihood of forming the particles into an unusable solid cake, although it does not always prevent this from happening. Some manufacturers sell reactors for this purpose. Some aquarists that have used the GFO in a traditional media bag report that it formed a brick in short order. Such caking may relate to calcium carbonate precipitation, or even to bacteria that are known to be able to knit the surfaces of two small iron oxide hydroxide particles together into a single particle."

Has anyone seen this happen? This is a nice theoretical possibility, but if it doesn't consistently happen then why worry (like worrying about toxic gas pockets in sand in freshwater, no one wants to worry about it, but it happens).

I think a real experiment will be more valuable. If anyone wants to setup what I described we could get real answers in as little as a few weeks.