Causes for high aluminum

[Luminous74]

“I'm not a scientist or an academic – I try to approach things with common sense as much as possible. That doesn't always work. In my humble opinion, after several years of reefkeeping, I've learned that most chemists aren't biologists, and most biologists aren't chemists. What we probably need is a trained marine biologist, microbiologist, and chemist – all in one person. But I'm not sure a single lifetime would be enough for that. I also become cautious whenever someone claims to know everything.
Because honestly: who can say for sure what the microbes in our tanks are really doing with all these chemical elements? And what about organic chemistry – how much of that are we even considering?”

 

[Luminous74]

This is why overgeneralization and trying to extrapolate something from someone else’s tank doesn’t always work.

You might have a different pathogenic bacteria strain that is fueled by carbon dosing. There are some tanks that can’t tolerate carbon dosing.

Sometimes switching the source can help.



Dinoflagellates do NOT consume silica. They do not have silica frustules. There is no evidence to support that claim he made.

I highly suggest taking anything that member says with a grain of salt.

Thank you very much! I see it exactly the way you described it and completely agree with you. Happy reefing!

 

[Miami Reef]

“I'm not a scientist or an academic – I try to approach things with common sense as much as possible. That doesn't always work. In my humble opinion, after several years of reefkeeping, I've learned that most chemists aren't biologists, and most biologists aren't chemists. What we probably need is a trained marine biologist, microbiologist, and chemist – all in one person. But I'm not sure a single lifetime would be enough for that. I also become cautious whenever someone claims to know everything.
Because honestly: who can say for sure what the microbes in our tanks are really doing with all these chemical elements? And what about organic chemistry – how much of that are we even considering?”

Whose quote is that? :)

 

[Luminous74]

Whose quote is that? :)

That came from my own pen – sometimes I try to be a bit deep.
Why? By the way, my initial comments were meant rather sarcastically, referring to the statements of certain people.
I hope my translator didn’t make any mistakes?

 

[Miami Reef]

Why?

It was profound. I liked it.

 

[Randy Holmes-Farley Verified Community Expert]

. It is reported that for conditions around neutral pH, residual aluminium concentrations are present in alumina treated waters in the range of 0.1–0.3 mg/L (using alumina columns) by Agarwal et al. (1999) and 0.01–0.05 mg/L (in AA domestic defluoridation units) by Kumar and Verma (2004).

https://www.sciencedirect.com/science/article/abs/pii/S0043135410001491

 

[Luminous74]

Es hat mir gefallen

Vielen Dank dafür. Ich schätze dieses Forum, seine Moderatoren und seine Mitglieder sehr – und ich habe hier schon viel gelernt.“

 

[Randy Holmes-Farley Verified Community Expert]

These folks only test at pH 6 and below, but they show dissolution of alumina at all pH values tested (Figures 4 and 6), and it is accelerated greatly by the presence of organics.

The coordination chemistry of weathering: I. Dissolution kinetics of δ-Al2O3 and BeO​

https://www.sciencedirect.com/science/article/abs/pii/0016703786902437

 

[commod0re]

So we are changing gears from claiming bauxite is insoluble to what material? I’m not going to chase every material one after another.

Do you know what exactly Phosguard is? No. So we will just be fishing around.

Pick one and I’ll see what I can find, but that doesn’t mean it applies to any materials reefers use unless you know exactly what they are.

You’re the one intentionally being vague here not me, I am merely trying to make sense of what it is you think you’re saying in relation to what I had posted. If you have a source that shows that either aluminum oxide reacts into hydroxide and then dissolves in normal seawater conditions, please share it, because my understanding is that the reaction does not occur unless the pH of the water is below 5 and if your aquarium measures pH 5 then you have bigger problems than free aluminum

If aluminum oxide actually reacted into hydroxide in normal seawater conditions it would not be possible to make boats out of aluminum and the materials data would not claim so plainly that aluminum oxide is the protective layer that prevents aluminum from significantly corroding.

By the way, what is it that bauxite is made from again? Those minerals all contain aluminum oxide

 

[commod0re]

L

These folks only test at pH 6 and below, but they show dissolution of alumina at all pH values tested (Figures 4 and 6), and it is accelerated greatly by the presence of organics.

The coordination chemistry of weathering: I. Dissolution kinetics of δ-Al2O3 and BeO​

https://www.sciencedirect.com/science/article/abs/pii/0016703786902437

where in the ocean exactly is the pH that low and has it been successfully replicated in an aquarium to also support typical marine life? If not this is irrelevant to the point where I’m not sure you understand the materials you’re referencing well enough to apply them appropriately

 

[Randy Holmes-Farley Verified Community Expert]

OK, one last paper. Seems they are not that hard to fiind.

This one uses alpha alumina. They found 0.089 mM Al in water at pH 7.2 at room temp. 0.089 mM = 2.4 ppm.

Dissolution behavior of α-alumina in solutions containing Mg2+ ions
https://www.jstage.jst.go.jp/article/jcersj1988/103/1200/103_1200_782/_article/-char/ja/

Abstract:

Dissolution behavior of high-purity α-alumina particles was studied in acidic solutions (pH 2.6-5.5) and basic solutions (pH 7.2-9.3) containing Mg2+ ions at room temperature. The amount of dissolved α-alumina was dominated by the solubility limit of aluminium hydroxide formed on the surface of α-alumina. The α-alumina in an acidic suspension of 5 vol% solids dissolved to increase pH of the suspension and to produce a supersaturated solution of Al3+ ions in which nucleation and growth of aluminium hydroxide proceeded until the Al3+ concentration reached the solubility limit of aluminium hydroxide. Little adsorption of Mg2+ ions onto the positively charged alumina surface (<0.5μmol/m2) was examined in the acidic suspensions at pH 4.1-4.3. The amount of alumina dissolved in the basic suspensions was less than that in the acidic solutions. Weakly charged negative alumina surface of 1m2 in the basic suspension at pH 7.9 adsorbed Mg2+ ions of 1.9μmol.


From the body of the paper:

Figure 4 also shows Al02- concentration in 5 vol% basic suspensions. As compared with the A13+ concentration in acidic suspensions, the dissolution of alumina was suppressed in the basic suspensions. The pH of suspensions reached a constant value of 7.1-7.2 after 25-49h of immersion time from initial pH 9.3. The decrease of pH with immersion indi cates the release of H+ ions from alumina surface. The Al02- concentrations at pH 7.15 in the suspension after 73h of immersion was calculated to be 0.089mmol/l using Eq. (6). The experimental result was about 1/2 of the calculated A102 concentra tion. However, the relatively good agreement of Al concentration between the experimental results and the calculated value based on Eqs. (1) and (2) indi cates that dissolution of A1203 is dominated by its sur face reaction expressed by Eqs. (1) or (2) through the formation of Al(OH)3 layer (A1203+3H2O 2Al(OH)3).

 

[Randy Holmes-Farley Verified Community Expert]

You’re the one intentionally being vague here not me, I am merely trying to make sense of what it is you think you’re saying in relation to what I had posted. If you have a source that shows that either aluminum oxide reacts into hydroxide and then dissolves in normal seawater conditions, please share it, because my understanding is that the reaction does not occur unless the pH of the water is below 5 and if your aquarium measures pH 5 then you have bigger problems than free aluminum

If aluminum oxide actually reacted into hydroxide in normal seawater conditions it would not be possible to make boats out of aluminum and the materials data would not claim so plainly that aluminum oxide is the protective layer that prevents aluminum from significantly corroding.

By the way, what is it that bauxite is made from again? Those minerals all contain aluminum oxide

I have already posted multiple references in this thread.

You are making the same mistake that many others have made. You are in good company. even Eric Bornemann stated that silica could not possibly dissolve or else the glass of our aquaria would dissolve. But, of course, it can.

The issues are two fold (at least):

1. there is already a lot of aluminum in natural seawater

2. the kinetics is slow.

No one is suggesting that a mm dissolves off a boat every day. But if a micron dissolved away every day, would a boat care?

 

[commod0re]

. It is reported that for conditions around neutral pH, residual aluminium concentrations are present in alumina treated waters in the range of 0.1–0.3 mg/L (using alumina columns) by Agarwal et al. (1999) and 0.01–0.05 mg/L (in AA domestic defluoridation units) by Kumar and Verma (2004).

https://www.sciencedirect.com/science/article/abs/pii/S0043135410001491

> Aluminium based adsorbents such as poly aluminium chloride, poly aluminium hydroxyl sulphate, alum sludge (aluminium hydroxides), activated alumina and alumina impregnated with various oxides (manganese, magnesium, ferric hydroxides etc) are found to be suitable for defluoridation of water

Do you even read these before posting them? This paper does not represent an analysis of a reaction of aluminum oxide into hydroxide in regular seawater conditions, nor leaching of alumina into seawater directly, this relates to a very specific chemical process involving the removal of fluoride from potable water

 

[Randy Holmes-Farley Verified Community Expert]

L

where in the ocean exactly is the pH that low and has it been successfully replicated in an aquarium to also support typical marine life? If not this is irrelevant to the point where I’m not sure you understand the materials you’re referencing well enough to apply them appropriately

Come on, you stated that alumina never dissolved except at extremes of pH and temperature. Now you pick apart one reference at pH 6 and room temp as not being exactly the pH you want.

OK, move on to other references I posted. The most recent one used alpha alumina and started at pH 9.3 that dropped to 7.2 during the test. Seems close enough.

 

[Randy Holmes-Farley Verified Community Expert]

> Aluminium based adsorbents such as poly aluminium chloride, poly aluminium hydroxyl sulphate, alum sludge (aluminium hydroxides), activated alumina and alumina impregnated with various oxides (manganese, magnesium, ferric hydroxides etc) are found to be suitable for defluoridation of water

Do you even read these before posting them? This paper does not represent an analysis of a reaction of aluminum oxide into hydroxide in regular seawater conditions, this relates to a very specific chemical process

Did you read it? Or are you just tossing up the abstract as a fake out?

They tested alumina in simulated drinking water:

Batch defluoridation experiments were carried out usingspecific dosages of alumina treating varying fluoride water solutions for AAD Simulator validation. The activated alumina used for defluoridation was procured from Bharghava Industries Limited, Surat, of grade FB101. The specifications of the alumina are given in following Table 2.

Table 2 – Specifications of FB101 grade alumina.
S No Particulars Specification1.
Particle form Spherical2.
Particle size (mm) 0.4–1.2 mm3.
Water adsorption capacity at 30C and60%RH by weight19.834.
Surface area sq.m/gm (minimum) 2605.
Pore volume cc/gm 0.436.
Bulk density gm/cc 0.82–0.877.
Bed crushing strength % 99.88.
Loss on attrition 0.1459.
Loss on ignition (250C to 1000C) 7.3310.
Chemical analysisAl2O3 by difference 92.34
Na2O 0.10
Fe2O3 0.03
SiO2 0.03

 

[commod0re]

So then where in the ocean exactly is there a pH below 6? Is there such a place and does it support coral life? If not then it seems highly irrelevant to the aquarist unless you can show that it happens under normal ocean/aquarium conditions. So far you have only actually proven my point, which is that under normal circumstances it doesn’t happen, the conditions required for it are exceptional, such as within specific chemical processes, with specific formulations of alumina, or under specific and frankly extreme conditions

 

[Randy Holmes-Farley Verified Community Expert]

So then where in the ocean exactly is there a pH below 6? Is there such a place and does it support coral life? If not then it seems highly irrelevant to the aquarist unless you can show that it happens under normal ocean/aquarium conditions. So far you have only actually proven my point, which is that under normal circumstances it doesn’t happen, the conditions required for it are exceptional, such as within specific chemical processes, with specific formulations of alumina, or under specific and frankly extreme conditions

This is getting tedious. Are you interested in getting at the truth, or just fighting to the death to try to prove me wrong?

You said it only dissolves at extremes of pH and temp. I showed it dissolves at room temp an at pH 6. NOT THE EXTREMES you claimed.

I also showed it dissolves at pH 9.3 and dropping to pH 7.2 during the test, at rom temp. Seems very close to me.

i showed that bauxite that you and Mike tout, is composed in large part by gibbsite. I showed that gibbsite can dissolve at all pH levels including seawater pH, to give levels consistent with what reefers observe.

I posted other papers with other scenarios and you ignore them or pick at minor details.

you have not posted a single experiment that shows anything incorrect about my claims. Finding a site that says something is insoluble shows nothing without knowing what criteria they use, and the standard use of the term insoluble would apply at the dissolved levels of aluminum that the papers I showed report for alumina.

Since I have shown here and in many other places who I am, how about some info on you?

You just joined and many of your posts are in this thread. Who are you?

Do you know Mike Sydney outside of reef2Reef? You both seemed to come out of nowhere to attack these aluminum threads that have been basically the same discussion for 20 years without anyone except Seachem fighting them so strongly

Do you work for any company that makes or sells aluminum-containing materials to the reef hobby?

 

[commod0re]

Did you read it? Or are you just tossing up the abstract as a fake out?

They tested alumina in simulated drinking water:

Batch defluoridation experiments were carried out usingspecific dosages of alumina treating varying fluoride water solutions for AAD Simulator validation. The activated alumina used for defluoridation was procured from Bharghava Industries Limited, Surat, of grade FB101. The specifications of the alumina are given in following Table 2.

Table 2 – Specifications of FB101 grade alumina.
S No Particulars Specification1.
Particle form Spherical2.
Particle size (mm) 0.4–1.2 mm3.
Water adsorption capacity at 30C and60%RH by weight19.834.
Surface area sq.m/gm (minimum) 2605.
Pore volume cc/gm 0.436.
Bulk density gm/cc 0.82–0.877.
Bed crushing strength % 99.88.
Loss on attrition 0.1459.
Loss on ignition (250C to 1000C) 7.3310.
Chemical analysisAl2O3 by difference 92.34
Na2O 0.10
Fe2O3 0.03
SiO2 0.03

Did you? Because the focus of this paper is actually on developing a model to predict defluoridation rates for drinking water, and specifically mentions that the presence of fluoride is a key factor for these circumstances. This does not actually provide any evidence that aluminum oxide dissolves in normal ocean water conditions. It also doesn’t go into any particulars about the form of aluminum detected in the water afterwards while validating the model, so it doesn’t seem to actually support what you’re saying. Another key difference between potable water and seawater that you are glossing over is that potable water has generally also been treated with chlorine, which will cause pitting corrosion with aluminum oxide and is a great reason to avoid using tap water in any aquarium

I will concede at least that I have not ruled out any forms of mechanical erosion, and this could in fact cause problems, but not due to aluminum toxicity

Now as for papers that are truly relevant here is one that demonstrates directly that there is no detectible aluminum released from alumina under reef conditions: https://e-lss.jp/seachem/downloads/articles/Aluminum-Solubility-Toxicity.pdf
The only way they were able to measure any free aluminum in the water was to triple the dose and use a pH below 6. A triple dose at a representive pH still produced zero measurable aluminum leaching

So I say again, you’re spreading FUD and citing references you clearly either didn’t fully read, or don’t understand

 

[Miami Reef]

Question: What is the white cloud that gets released upon adding Seachem’s Phosguard to a reef tank?

 

[ReneReef]

https://e-lss.jp/seachem/downloads/articles/Aluminum-Solubility-Toxicity.pdf

That is not a scientific peer reviewed journal article.
It's written and published by Seachem, a company with a vested interest to deny aluminium leaching from their products in the face of overwhelming independent evidence to the contrary.