Granular ferric oxide differences. Phosphate removers

SATAN FISH · 11/04/2009, 09:17 PM

So... me being a broke bastard, I decided to buy this granular ferric oxide.
http://cgi.ebay.com/GFO-Granular-Fer...item3a52edfe9c

It is 5lbs. Since Bulk Reef Supply offers 4lbs and it takes up the volume of one gallon, I figured this stuff would take up 1 1/4 gallons. Needless to say, I was a little shocked when it showed up in two little bags. Probably a total of 5 cups worth. I weighed it to make sure, and each bag does in fact weigh 2.5 lbs, but is nowhere near 1 gallon worth of volume.

Here is Bulk Reef Supply's add for their 4 lb 1 gallon container.
http://www.bulkreefsupply.com/Carbon...duct_info.html

My question is this. Are there different granular ferric oxides out there? I mean obviously there must be. The stuff I have must be really dense compared to BRS. Does anyone know if BRS 4lbs is actually a one gallon container worth? I was under the impression that GFO was GFO no matter where you get it. How do you think they will compare when absorbing phosphates?

bertoni · 11/05/2009, 08:08 PM

There isn't any data on the effectiveness of the various GFO products, but surface area is critical, since phosphate is adsorbed only onto the surface. I suspect the density of your product indicates it has little surface area, and thus won't be very effective, but I don't know for sure. Most of the better-known commercial products get reasonable reviews, including BRS.

11/04/2009, 09:17 PM	#1
SATAN FISH Registered Member Join Date: Jun 2009 Location: Denver CO Posts: 206	Granular ferric oxide differences. Phosphate removers So... me being a broke bastard, I decided to buy this granular ferric oxide. http://cgi.ebay.com/GFO-Granular-Fer...item3a52edfe9c It is 5lbs. Since Bulk Reef Supply offers 4lbs and it takes up the volume of one gallon, I figured this stuff would take up 1 1/4 gallons. Needless to say, I was a little shocked when it showed up in two little bags. Probably a total of 5 cups worth. I weighed it to make sure, and each bag does in fact weigh 2.5 lbs, but is nowhere near 1 gallon worth of volume. Here is Bulk Reef Supply's add for their 4 lb 1 gallon container. http://www.bulkreefsupply.com/Carbon...duct_info.html My question is this. Are there different granular ferric oxides out there? I mean obviously there must be. The stuff I have must be really dense compared to BRS. Does anyone know if BRS 4lbs is actually a one gallon container worth? I was under the impression that GFO was GFO no matter where you get it. How do you think they will compare when absorbing phosphates? __________________ _____________________________________________________ 125gal 6ft tank, 20gal refugium, ETSS sump bud 60 250w MH 15k x 3 39w T5 actinic x 8 170lbs live rock Pacific blue tang Yellow tang Ocellaris clowns, one black, one orange Six line wrasse Fire fish Fire shrimp Royal Gramma Purple psudochromis Starry Blenny Mostly LPS and softies. One yellow turbinaria Current Tank Info: Reef tank going since June 09

11/05/2009, 08:08 PM	#2
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	There isn't any data on the effectiveness of the various GFO products, but surface area is critical, since phosphate is adsorbed only onto the surface. I suspect the density of your product indicates it has little surface area, and thus won't be very effective, but I don't know for sure. Most of the better-known commercial products get reasonable reviews, including BRS. __________________ Jonathan Bertoni