Hi,
Macro examples are Nitrogen and Phosphate (N,P), etc.
Micro examples are the trace elements like iron, magnesium, boron, etc.
Macros are used in more of the plant functions and generally more are taken in by the plants than the micros. Thus macros are dosed in greater quantities than micros generally speaking.
Micros are also replenished by a water change.
Hope this helps.
