Often mentioned, but its function is still not very well understood in a saltwater tank.

What we do know is that amino acids are the building blocks of protein, not just in our aquariums but in life in general, but that the benefits of amino acids in your tank can only be assumed (as far as I can understand).

Do I need to dose amino acids?

Every time you feed your fish, you are introducing amino acids into your system, however biosynthesis plays a larger role in production of amino acids.  Biosynthesis is the ability of the symbiotic zooxanthellae, hosted by the corals, to produce amino acids.  The question is, does your system facilitate the ability of zooxanthellae to produce enough amino acids?

In the end it comes down to whether or not you think your tank may be deficient in amino acids.  This deficiency may be due to running a ULN (Ultra Low Nutrient) system with very little nutrients available for coral uptake.
The addition of amino acids in a deficient system may well be beneficial, but there is no definite answer.

I have chosen to use amino acids, dosing daily, because I do run a ULN system.
My thought process is I would rather ensure the amino acids are available for uptake than have a system that is potentially deficient, essentially doing what I can for my corals. My corals are very healthy, however without the luxury of a like for like tank it would be hard to me to say with any certainty that it has made any difference.
I may well be wasting my money?

Although amino acids are such a grey area, it hasn’t held all the established brands back from producing it and selling it.  These brands include Red Sea Energy A and B, Acropower by Two Little Fishies, Nyos Absolute Aminos and Aquaforest AF Amino Mix to name a few.

I use Acropower simply because it doesn’t need to be mixed prior to use, so it is suitable for use with an automatic doser.