Elevated aluminum

[lolmatt]

Here's the post I'm referring to where Ryan "confirmed" that marinepure leeches Al:

https://www.reef2reef.com/threads/i...brstv-investigates.307515/page-4#post-3814988

 

[915MANG]

Whats sup Matt, Interesting!

 

[Scott Campbell]

The thing with Marine Pure blocks is that they are a ceramic material. Which is composed of alumina-silicates. Alumina-silicate dust is not particularly reactive at a pH of 8 (as noted above). But a Triton test will read alumina and aluminum as the same element. Alumina-silicate dust might irritate the crap out of some corals. At least for a while until the dust settles out. But it is not toxic like aluminum.

What BRS discovered is that Marine Pure blocks release some form of alumina and/or aluminum into the aquarium. But no way to tell whether it is toxic aluminum or relatively inert alumina-silicates. What BRS also discovered is that the thinner blocks release a *lot* more alumina/aluminum than the spheres or thicker blocks for the same volume of material. Assuming the spheres, thin blocks and thick blocks are all made from the same material; they should release aluminum into the water roughly proportional to the volume of ceramic material added to the aquarium. But they don't. If it is particulate ceramic dust being released into the aquarium, then it does make sense that the thinner blocks are releasing a lot more alumina than the spheres. The spheres are a molded shape and not particularly fragile. The blocks are an extrusion which are sawed or cut into different thicknesses. The cutting process clearly degrades the integrity of the block. The thin blocks are especially fragile. You can just look at the thin blocks and see the dust. And finally, BRS showed that the Marine Pure blocks were also releasing silica into the aquarium. In proportions relative to alumina that would reflect common ceramic materials.

Certainly dumping a bunch of ceramic particulate matter into an aquarium will have short-term consequences. I expect many corals, clams, etc. would be irritated. Perhaps extremely irritated. And some alumina-silicate material will be reduced to toxic aluminum no matter the pH. Especially if you add enough ceramic material. But it is very likely most of what BRS registered on their Triton tests was fine particulate alumina-silicate dust rather than toxic aluminum. I have a bunch of Marine Pure spheres in my sump and I have never had a Triton test indicate aluminum in my aquarium. That all said - the Marine Pure company doesn't seem especially knowledgeable about their own product. Which certainly doesn't help their cause.

 

[lolmatt]

My biggest problem is the company hasn't acknowledged the alleged issue at all - they still claim 100% inert, will not leach, etc. I'd personally want to see a disclaimer that says the product can let off fine particulate non toxic alumina before using the product. I think an extruded glass media is the safest bet until MP has some more concrete data behind it.

 

[Jose Mayo]

Has anyone done experiments with the use of "chitosan" for adsorption of aluminum (and other metallic ions) in aquarism?

Chitosan is a polymer derived from chitin, contained in shrimp shells and other crustaceans, subjected to a strong alkali, such as sodium or potassium hydroxide. This polymer is already used in some food compositions in aquarism, but ... in several studies of adsorption of aluminum in wastewater, has proved to be very effective:

Study of the removal of residual aluminum through the biopolymers carboxymethylcellulose, chitin, and chitosan

Curious about whether this polymer has already been tried for this purpose in aquarism.

The idea was perhaps to open the capsules and put their contents in a bag of media, like the one used for Purigen, for example, put in the sump for a few hours and check what happens ...

Best regards

 

[Randy Holmes-Farley]

The idea was perhaps to open the capsules and put their contents in a bag of media, like the one used for Purigen, for example, put in the sump for a few hours and check what happens ...

I've not seen anyone try it. It might well be worth testing, but this article isn't very convincing that it would necessarily work.

The main tests (not the kinetic tests in well water) were done with only aluminum sulfate in the water (no other ions competing for binding sites), and aluminum will be in a different form with a different charge in seawater (AL(OH)4- and Al(OH)3) than it was in these studies (Al+++, AL(OH)2+, Al(OH)++).

 

[Jose Mayo]

I've not seen anyone try it. It might well be worth testing, but this article isn't very convincing that it would necessarily work.

The main tests (not the kinetic tests in well water) were done with only aluminum sulfate in the water (no other ions competing for binding sites), and aluminum will be in a different form with a different charge in seawater (AL(OH)4- and Al(OH)3) than it was in these studies (Al+++, AL(OH)2+, Al(OH)++).

Yes, the marine context may make everything different, but since this material is derived from an organic material of marine beings, it is at least to be expected that it will not be toxic nor will it alter the parameters of water very much ... it may be worth trying , IMO, and if you have any good results, it can be a good acquisition for the hobby.

There are many other articles and reports on the adsorption of chitosan in waste water for metal ions, but I have not found any of them in marine water.

Best Regards

 

[Randy Holmes-Farley]

Yes, the marine context may make everything different, but since this material is derived from an organic material of marine beings, it is at least to be expected that it will not be toxic nor will it alter the parameters of water very much ... it may be worth trying , IMO, and if you have any good results, it can be a good acquisition for the hobby.

Best Regards

I agree it won't hurt anything, assuming it is a higher molecular weight that will not simply dissolve (low molecular weights will). I am very familiar with chitosan since I have used it (along with thousands of similar polymer materials) in experiments in binding things as potential human therapeutics.

 

[BZOFIQ]

@Randy Holmes-Farley

What about this product? Aluminum is listed on the list of metals it removes.

https://amzn.to/3E0aXdF

 

[Randy Holmes-Farley]

@Randy Holmes-Farley

What about this product? Aluminum is listed on the list of metals it removes.

https://amzn.to/3E0aXdF

I do not know how effective it is for aluminum in a reef tank, or even if the aluminum is taking a bindable form, but it generally is a fine metal binder to try.

 

[BZOFIQ]

I found more info from what looks to be a manufacturer. Looks like it was designed to remove large quantities of metals.

Metasorb UHC – Periodic Products

periodicproducts.com

Chelok® Polymer – Periodic Products

periodicproducts.com

 

[Randy Holmes-Farley]

It's a fine product, but as I said, binding aluminum is tricky since it is not even clear that aluminum in reef tanks is present as individual ions that can be bound, or as some sort of particulate that is unlikely to be readily bound.

 

[BZOFIQ]

It's a fine product, but as I said, binding aluminum is tricky since it is not even clear that aluminum in reef tanks is present as individual ions that can be bound, or as some sort of particulate that is unlikely to be readily bound.

If its particulate wouldnt a micron sock or skimmer remove it?

Either way, the product is on its way to me.

 

[Randy Holmes-Farley]

If its particulate wouldnt a micron sock or skimmer remove it?

Either way, the product is on its way to me.

No, it may be much finer than a sock opening size.

 

[BZOFIQ]

No, it may be much finer than a sock opening size.

Got ya.

I've used 1 and 5 micron in not so distant past with Lanthanum Chloride and it didn't remove the Aluminium so yeah if particulate it would be much smaller than a micron.

I'll use the above mentioned media for 7 days and do an ICP after. Hoping to be blown away with metals "stripped" out of the water column.