My second post....
I know from experience Triton supplements are extremely high quality and pure. They also tally with the remediation instructions on their ICP, so I know exactly how much to dose to correct.
You only need to look at the contaminants and screwy levels reported in independent ICP testing of salts to see what contamination or variation can look like.
I agree that contaminants are likely to be coming from other sources, but it's not unheard of for amino, element supplements etc to have all sorts of things you didn't know you were putting in your tank. If you have a known good supplier and are happy with it, then carry on using them. However ICP testing has been an eye opener for me and the Triton elements are of known good quality, hence why I use them.