For every one that says one thing, there is another claiming the opposite. Most of what I have read on these exact items says they do not have aluminum issues. I have had mine in since I first set my system up. Being new to the hobby, I cannot say what they are doing good or bad. However, I have had some issues with coral in my tank, but cannot say it is those. Going forward, I have a better sense of keeping the system stabilized, and the system is more established now so if things don't go well, I would suspect them further. I have ordered and am having sent away the Fauna Marin full test kit which does more than the Triton test kits. In a week or so, hopefully I will see full lab results. See what turns up there. If there is Aluminum in there in any relevant concentration, they will most certainly come out. I am switching from Red Sea Coral Pro to Fauna Marin salt so will do another of the same test in about 3 months to see any differences.