the benefits of EI dosing are well explained elsewhere - but in a nutshell, all nutrients are present in excess so plants won't develop deficiencies, and if co2/lighting/flow/maintainence are all appropriate there shouldn't be a problem with algae. but i know some of you use other dosing methods. just interested why? is it just habit, i know a few of you are given commercial preparations free, but are there other reasons? for example why do some of you use PMDD over EI (apart from saving a few pennies on less dry ferts)? thanks.