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View Full Version : Ferric Oxide or Ferric hydroxide

Lionard
12/20/2004, 05:55 AM
Dear all,

Can you help me to answer my question :
Is it same between Ferric Oxide and Ferric Hydroxide ?
and if I have Ferric Oxide, can I use it to bind phosphate in my reef tank.

Please help me !
Thks
Best Regards
Lionard
Mr James
12/20/2004, 07:38 AM
Dude, post that question in the Chemistry Forum!! Randy would probably kill for a question other than calcium and alkalinity!!
sjfishguy
12/20/2004, 12:48 PM
Ferric oxide is a fancy way of saying rust. Ferric oxide (Fe203) and ferric hydroxide(FeOH3) are not the same thing. I dont think either one binds phosphate (if one them does, I would be interested in seeing the mechanism). You can ask others to confirm this though.
mhurley
12/20/2004, 02:07 PM
[moved]
Randy Holmes-Farley
12/20/2004, 02:17 PM
Ferric oxide is Fe2O3.

Ferric hydroxide is Fe(OH)3

The iron based phosphate binders contain both oxide and hydroxide groups. I describe them in detail in this article:

Iron Oxide Hydroxide (GFO) Phosphate Binders
http://reefkeeping.com/issues/2004-11/rhf/index.htm

If you have particulate iron oxide or hydroxide, it will bind phosphate to its surface. The critical factors are the surface area, and the particle size.

Too small of particles will get into the water and turn it brown with suspended iron oxide hydroxide particles.

Too small of surface area will not bind much phosphate.

The GFO sold commercially attains both of these goals with a high surface area material held in reasonably large, porous particles.
Lionard
12/20/2004, 09:24 PM
Dear all,

Sorry if I post my question in wrong chapter of this forum.
But I want to say thks you very much for all reply about my question.

Once again, thanks for all attention about my statement or question.

Best Regards
Lionards
Randy Holmes-Farley
12/21/2004, 08:03 AM
No problem, Lionards. The moderators sometimes move posts around to better fit into a particular forum. :)

You're welcome and happy reefing. :)
BIGGUN
01/30/2005, 11:38 PM
So is the brand name stuff for aquariums different than the GFO used in the coatings industry, or is GFO just GFO?

I have access to Iron oxide/hydroxide just wonder if it would be useful or not?

Kevin
Randy Holmes-Farley
01/31/2005, 08:43 AM
The commercial brands are not all identical in appearance, and I wouldn't assume they are all the same in use, although I've not seem data that distinguishes them.

The most important aspect, IMO, is to have a very high surface area in a suitably large particle that it does not get loose into the tank and turn it brown.