ROWAphos or BRS GFO ??

[bif24701]

I just about to get me reactors but what product is better ROWAphos or BRS GFO?? I am currently fighting cyano and GHA.

[2thdeekay]

It's mostly preference, but I much prefer rowaphos over BRS's regular GFO, but like their HC too. Many prefer their HC or pelleted gfo.

[Randy Holmes-Farley]

I prefer the pellet GFO from BRS over Rowaphos due to size as I use it in a cannister filter, but there is little to no available data on performance issues.

[tmz]

I prefer the HC from BRS. Relatively little dust.It's heavier and doesn't grind up very much or melt much when regenerating it.ime.

[Boomer]

Based on some unpublished studies by jd Rowa is better than all others par HC GFO. From all the reading research I did for the Stienhart I came up with the same answer as jd.

[bertoni]

Any chance any of the data will be published? Do you mean the Steinhart in Golden Gate Park?

[kevin28]

rowa is better for the reason it wont leach back, I checked with BRS and they said theirs will leach back,

[Boomer]

Jon
Yes, that aquarium. It has notihng to do with the study and does not envole them at all. It was for me to explain the different kinds of GFO to them and how they vary, to include GAC. I doubt jd, Jose D will ever publish it. It was for his own interests.

Kevin
BRS is lost, it has to.do with adsorption capacity. Leaching is on another planet

[Randy Holmes-Farley]

rowa is better for the reason it wont leach back, I checked with BRS and they said theirs will leach back,

Not true. I've demonstrated in my own experiments that Rowaphos can release phosphate back to the water, and that is going to be true of every brand. There is nothing a company can do to prevent that.

[ksed]

Is the key here to replace the GFO before it gets saturated.If so it seem very difficult to know that saturation point?

Thanks

Kevin

Originally Posted by Randy Holmes-Farley

rowa is better for the reason it wont leach back, I checked with BRS and they said theirs will leach back,

Not true. I've demonstrated in my own experiments that Rowaphos can release phosphate back to the water, and that is going to be true of every brand. There is nothing a company can do to prevent that.

[aquatictec]

As far as I know there is only 1 patent out for making GFO and only 1 company makes it. Some people may sift it or wet it or rinse it but it all started out the same. There should be little if any difference between the performance from the various places selling it.

[jdyer88]

Originally Posted by aquatictec

As far as I know there is only 1 patent out for making GFO and only 1 company makes it. Some people may sift it or wet it or rinse it but it all started out the same. There should be little if any difference between the performance from the various places selling it.

Idon't think its a very involved process to make GFO...Many people make ferric oxide at home for the purpose of model rocketry. It involves a brine mixture, direct current electricity, and a sacrifical piece of steel. How to make it "granular" is probably a question for Randy

[kevin28]

My statement was made from the representatives of each of the company's,I have contacted both D&D and BRS as well as many others and the only one that " Claims " wont leach back is Rowa,but as with other company's it my be words to get you to buy there product.

[tmz]

Checking the Po4 level of the effluent water from the gfo reactor and comparing it to the level in the tank can let you know if it is still adsorbing PO4.

[bif24701]

Well from what I understand the GFO will absorb PO4 until it has meets the saturation point with the aquarium water once it has it will not absorb any more until the PO4 level drops or rises. BASICALY: If the PO4 level rises then the GFO will continue to absorb until it reaches the next saturation point. If the PO4 level falls then it is possible that the GFO will leach PO4 until it reaches the saturation point. Of course the level of PO4 within the GFO will be considerably higher than the surrounding water. From that you could say the saturation point depends largely on the amount of PO4 in the water at the time.

[Randy Holmes-Farley]

Is the key here to replace the GFO before it gets saturated.If so it seem very difficult to know that saturation point?


Phosphate binding to such materials is an equilibrium process. More phosphate in solution means more phosphate bound. These materials will typically only release the phosphate back if the water concentration is lower than what was used when it became bound, or if something else comes along and displaces it.

So net release is not all that much of a concern in normal use.

[ksed]

Thanks

[Boomer]

aquatictec

As far as I know there is only 1 patent out for making GFO and only 1 company makes it. Some people may sift it or wet it or rinse it but it all started out the same.

There are quite a few companies that make GFO and as of this time all are German.

The first product was AdsorpAs , developed at the Technical University of Berlin, Germany, Department of Water Quality Control, with Harbauer GmbH of Germany. AdsorpAs was conceived for 3rd World countries to remove Arsenic from water. Harbauer GmbH is also the manufacture and renamed it GFH, for marketing sales, which is sold through Siemens. US Filter use to sell it also but they have no merged with Siemens. This is what is called a "wet" GFO, as it has moisture. This is what ROWA is. Even their pic they use on the can is the same as that used by Siemens.

GFO =Granualr Ferric Oxide hydroxide

GFH = Granular Ferric oxide Hydroxide

These^ are the minerals Goethite and Limonite which are Iron(III). One is an anhydrous and the other a hydrated form. When hydrated they are given the (FeO(OH)·H2O, which is the same as (Fe(OH)3 only written different and called Limonite. The anhydrous is â-FeOOH or Goethite. There are also some other uncommon or rare forms. Most of all these are famous from where I use to work in the iron ore mines of northern Minessota, which includes even more forms of iron oxides,i.e., Magnetite ( Taconite), Hematite ( Natural Iron ore) that are heavily mined.

Now, when a mineral has the same composition and a different crystal form we call it a True Polymorph. Calcite is CaCO3 Trigonal and Aragonite is CaCO3 Orthorhombic and are true polymorph's, as both are in a different crystal class. Some minerals are not really true morph's, as they are in the same crystal class and have the same composition. This is the case with our Goethite, where a Greek symbol "a" , actually Alpha α, is added to the front to indicated there are other morph's. The other morphs are given different names like Feroxyhyte and Lepidocrocite, which have a different Greek symbol in front of its chem formula. Some do not like to go by mineral names and just give the composition but the reader needs to know that α-FeO(OH) is not the same as γ-FeO(OH), as all of these are Orthorhombic. That tells us they are morph's within the same crystal class.



Severntrent Services and Lanxess use to be a division of Bayer and produce 4 kinds of Bayoxide we use. All those in this hobby are Bayoxide par ROWA.

Bayoxide E33, E33P, E33HC, E IN-20


E33 and E33P are the std, E33 is granular and E33P is pellet form which is better for our application not that is adsorption rate is better. Severntrent does not have the new E33HC. You must go to Lanxess for that one.


The varying types of GFO are not the same and have difference adsorption rates just like GAC. Different ones for different applications. E33HC is the highest due to its increased pore structure and surface area for binding. This is followed by GFH. The other GFO are fairly lower in adsorption capacity.

There are also synthetic GFO called GEH, Granuliertes Eisen- Hydroxid. Where the addition of either FeCl3 or FeSO4 is used. There is crap loads of info and data on GFO you just need to look under the right name, Arsenic removers. There are also GFO that are polymer coated. The use of GFO for PO4 was an after thought.


There are performance data sheets on PO4. I have some/one someplace done by a Germany Lab that compares many GFO's.


I will add there are crap loads of thing that remove PO4, even GAC does, although not very good. It will bring a concentration of 3 ppm down to 2.7. Some things like Bone Char down to less than 1 ppm. GAC has about the same adsorption capacity as Limestone. As see in:

Phosphorus adsorption by natually- occurring materials and industrial products
by Mortual, J. Envior.Eng.Sci.Vol 6, 2007

And there are others like clay minerals. The amount of orthophosphate adsorbed by each of the clays increases in the following order: montmorillonite < kaolinite < illite
Phosphate and Tripolyphosphate Adsorption
by Clay Minerals and Estuarine Sediments
Carol A. Lake and William G. Maclntyre



jdyer88

I don't think its a very involved process to make GFO

It is allot more involved than you think it is and on the order of tryign to make GAC at home. You have to have a means to control the pore structure and pore volume to get proper adsorption or efficient adsorption. The Granular Ferric Hydroxide (GFH/AdsorpAs®) is poorly crystallized â- FeOOH manufactured from a ferric chloride solution by neutralization and precipitation with sodium hydroxide. As no drying procedure is included in its preparation, all the pores are completely filled with water, leading to a high density of available adsorption sites and thus to a high adsorption capacity i.e.,


GFH/AdsorpAs/ROWA
Active substance Fe(OH)3 and (â-FeOOH) : 52-57 %
Water content : 43-48 %

Phosphorus : typical 10g/dm3 adsorber bed, 16g/kg dry weight

Grain size : 0.2- 2.0 mm
Density of grains : 1.59 kg/dm3
Bulk density : 1.22 – 1.29 kg/dm3
Porosity of grains : 72 –77 %
Specific surface : 250 – 300 m2/dm3
Bulk porosity : 22b – 28 %

From ^Granular Ferric Hydroxide for Elimination
of Arsenic from Drinking Water
B. N. Pal

[Boomer]

I found one of them I have some/one someplace done by a Germany Lab that compares many GFO's.

ROWAPhos vs PhosBan
http://www.theaquariumsolution.com/f...n%20report.pdf

Found my other links and they are all dead

[jdyer88]

great link boomer

I was not clear at all in my previous post. I wasn't suggesting that anyone could just make gfo at home, I was only speaking to the fact that the patent mentioned in a previous post, was probably not issued for the process of making GFO. I was just trying to imply that the process for making GFO is probably not proprietary....I love the chemisty forum (when I understand what everyone is talking about, which is rare )

[Randy Holmes-Farley]

It's curious that the seawater graph (but not so much so the freshwater one) extends to enormous phosphate concentrations. Almost as if they needed to do that to "prove" that Rowaphos was better than Phosban, while under normal conditions (say, 0.03 ppm), the difference, if any, was not substantial enough to publish.

[Perrier01]

How many ROWAphos or BRS GFO (cup) should I use for the new 200g tank? I plan to have all SPS. I have both brands in hand.

[Randy Holmes-Farley]

Is phosphate elevated now, or is this just a precautionary measure?

[Necidemos]

Tomatoe, Tomato... They are both equally good, IMO.

[Boomer]

Randy

if any, was not substantial enough to publish.

I think you are grasping for straws You are insinuating that very reputably Germany water testing lab, the IWW, is deliberately doing this for ROWA to make their GFO look better. When it is probably more on the order that is just the way they test GFO. Granted it would have been nice to see more realistic reef tank levels. Not only that, but natural FW is about the same as your given~ 0.03, with a max of 0.1 ppm. I will add that jd found similar results on reef tank PO4 adsorption. However, the adsorption rates where not that dramatic as appears in the graphs when dealing with low levels. Are you reading that graph right At a P-Equilibrium of 0.5 ROWA P-Load is ~ 11.2 mg/ g solid and the PhosBan is only ~ 5 mg/g solid or twice as much ( see below)


Here is a pdf showing the same Iostherms as the one I posted at the same levels of P. See page 30. Look at plot d.) about the same.

From it;

Figure 8 d) shows phosphate adsorption isotherms for FerroSorp and Bayoxide
E33 (PhosBan) under identical conditions (DI water, pH 7). The results show that GFH(ROWA)
shows significantly higher capacities for phosphate adsorption (approx. twice as high solid-phase concentrations). This is in accordance with the significant lowerspecific surface areas of these adsorbents.

PHOSPHATE ADSORPTION ONTO GRANULAR FERRIC
HYDROXIDE (GFH) FOR WASTEWATER REUSE
http://www.google.com/url?sa=t&sourc...n4u13A&cad=rja