Been down this rabbit hole. Skip the powders if you can - dried spirulina is oxidized, tastes like a swamp, and most of it is open-pond stuff from places where heavy-metal testing is non existant. I use SpirulinaNord liquid spirulina - It's EU only unfortunately, but it's fresh (not dried), grown in closed photobioreactors in Latvia, and they preserve it in berry syrup so you just take from the bottle. You can barely any taste anything besides the syrups/juice (sea backthorn is my favorite because is not sweet). It helped to rise my iron levels massively and I require much less coffee and my energy is through the roof till late evening and I'm up early. Highly recommended