Originally Posted by glassguppy
What does EI mean?
A fertilizing method based on a concept that excess in any* nutrient,
either in water column or substrate, doesn't cause algae.
Other "methods" of fertilizing may use the same ingredients (dry ferts) as EI.
But this is THE distinction that set it apart from other "schools".
And test kits are not needed, some even anti using them.
More info on the barrreport.com
*Except ammonia/ammonium in the water column.