I have been using two additives, Acropower and VitaChem. The former is a combination of amino acids and the latter is vitamins. Is there any overlap in these? What is the difference between vitamins and amino acids?
Amino acids are the building blocks of proteins. Vitamins are organic molecules that are used by some organisms, but do not become incorporated into tissues in most cases. Amino acids are a source of nitrogen, and can be especially useful in ULNS (very low nutrient) tanks. I've not seen evidence that most dosed vitamins are useful, but they may be.