GFO vs AO

Ace25

Ace25

www.centralcoastreefclub. com
Oct 3, 2005
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www.centralcoastreefclub.com
Ok, I am having a real hard time finding any real world negatives to using Phosguard (Aluminum Oxides, AO) if used properly. I do see real world negatives with using Phosban / Rowaphos (Granular Ferric Oxides, GFO) which is the lowering of Alk/pH levels. Here are the old articles I am referencing.

Phosguard Article
http://www.advancedaquarist.com/issues/july2003/chem.htm

GFO Article
http://www.advancedaquarist.com/issues/june2004/review.htm

2 things, the articles are very old now, and also they really don't draw any conclusions to say if AO is used properly is any worse than say feeding Brine Shimp in your tank. There is another study, performed by Seachem, which states NO aluminum is released when using Phosguard as long as your pH is 8+. I just can't trust a Mfg study on their own products though, especially when other studies show it does in fact release aluminum into your tank, it just doesn't seem to release enough of it to really be concerned about IF used properly. You would literally need to use 51x 1-liter bottles of phosguard on a ninety gallon aquarium for one week to achieve known toxic levels, and this is makng the assumption that the released aluminum is in soluble form.. Who would even consider doing that? The costs of the media alone would tell me no one in their right mind would ever think of doing that.

Can anyone point to me exactly how and why Phosguard has such a bad rap when so many other things, including our food and salt mixes, contain aluminum in them as well. The perceived risks of AO seem slim to none if used properly. Anything can be toxic in a tank if there is enough of it, heck, freshwater is toxic in a SW tank if you take out 1/2 your water and replace it with freshwater.. the key thing I am reading is don't overdose, rinse well, and don't violently tumble it in a reactor and you will be fine.. but this is according to an article written almost 7 years ago. There has to be some newer information out there on this that I am just not finding that makes SW owners everwhere keep repeating "Phosguard is BAD to use!", right?
 
clearly you know the reasoning behind peoples dislike of AO, it seems to me that people are always so anal about what can go in a tank and what cant, this and that chemical are not found in nature and so and so but a lot of things people dose and incidently add to thier tanks are not easily measurable and really not everyone knows whats exactly in thier water.
who would think that you could add driveway salt to a tank to boost calcium?
if you can get over the fact that aluminum is in your tank there is still the increased iron benefit from using gfo, which supposedly boosts macro algae growth.
i personally use phosar because i dont have the space for a specialized reactor, i just run it passively in my hob which is more of a fuge i guess. the whole alk/ph issue doesnt really affect me i guess, i dose alk every day on an automated timer so i cant help you there.

it seems to me that the phosgaurd doesnt release any aluminum smaller than the 45 micron filter could pull out, meaning that the aluminum in the water was mostly pretty big i guess
 
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Thing is, AO releases aluminum into your tank, well, GFO releases IRON into your tank. Which one is more evil? I would think iron would be since it can rust, right? At least the particulate form. Isn't one of the biggest "no-no's" in SW aquariums is to put metal objects that can rust into your water, yet people put an iron based product in their tanks to remove phosphates. Makes me scratch my head as to the logic.

Dosing Alk on a timer doesn't really help when you change out GFO. On a timer, it is set to dose a certain amount all the time, well, that is fine when you have your system dialed into the consumption levels, but when you add fresh GFO is takes your Alk/pH down another notch and your timers aren't setup to account for this. This is mainly a concern for SPS corals. LPS and softies can handle Alk swings much better.
 
Still, that is severely overdosing phosguard, that is around a 1:6 ratio if phosguard to water. No one does that. (I assume you meant to put .05 as the starting point)

I have used GFO myself for many years and the only problems I experience are the ones already noted, the alk problems, but I mainly used it because I always seem to get yelled at when I mention the word "Phosguard" so I just became one of the sheep and followed the flock. Now I am finally starting to really question the use of GFO over AO but I would really like to see some good studies done that can definitively say one way or another if AO is that bad to use that it should not be used for extended periods of time in a SW aquarium.
 
The first link I posted was to Randy Holmes-Farley's first article on Aluminum, here is his second article.

http://reefkeeping.com/issues/2006-09/rhf/index.php

Here is his quote on AO usage:
That all said, many people use aluminum oxide effectively, and many never notice any negative effects. I have used it in the past without noticing harm in my aquarium, although I have used only small amounts. Rinsing it before use and not using large amounts all at once will limit any negative impact.
Click to expand...
 
Actually, aluminum is far, far more toxic than iron. It is actually more dangerous to vertebrates than invertebrates. I try to stay away from anything that contains aluminum.

FWIW, rusting components don't usually just contain iron, but various other metals, like chromium, zinc, copper, etc. that actually cause the issues.

Edit: I should also note that iron is usually very, very short lived in a soluble state in seawater and in our tanks. It usually precipitates or is utilized quickly.
 
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But that is just a "gut feeling" your going on, right Amph? Do you have any evidence or links to point me to that would actually prove AO can release enough aluminum into the tank to cause any issues if used correctly? It seems even Randy can't find any issues with using it if used properly.

I know you run a scrubber now, and from my reading that does seem to be the "safest" method to remove all sorts of nasty stuff in the water, but after "natural methods" of doing the job, what would be the best mechanical means?

Or more to the point, and original question, is AO worse than GFO if both are used properly? It seems GFO has more known problems when used properly than AO does, but AO has a much higher risk of causing a major problem if not used properly. Is that really what it all boils down to?
 
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