Not all aluminum, certain alloys of aluminum. It states this on the first page of that article. We also have a lot of organics in our aquariums that are much more diluted in the ocean. In the article it talks about organics causing oxidation problems with aluminum. I personally would never used aluminum in or around my tank, I have way too much money tied up in it to contaminate it. But ultimately it's your tank and you can decide what you are comfortable putting in it.