Are you planning to only automate macronutrients (or micronutrients)? Or do you have another dosing pump?
I assume you are aware you cannot mix the two together and dose them at the same time.
In general, the chemicals will not precipitate out, unless you make them very concentrated.
As long as the containers are well sealed, then you shouldn't run into any issues with air contamination either.
As for light contamination, you can just wrap the bottles in construction paper or something similar.
Thanks for the heads up, I was unaware that you cant mix macro and micro together outside the tank. I was planning on using something like a ball jar with an air hose to pull the macro into the tank.
I will start there because currently my micro in the tank is great, the macro is almost non-existant.
Thanks again for the help!