hey coop - i'm no pro, but from what i understand step one has an enzyme in it that promotes root growth. if this is true and not marketing bs, then step one should always be used when re-planting. step 2 departs mainly from step one by adding iron, but i like to use eca for iron instead. why do i spell out the number one but type the number 2? i have no idea. i digress. i'm dosing step 1, brighty k, and eca on newly planted stems in three year old eco complete, and everything is growing like crazy. so i dunno. i have step 2 waiting in the wings, so we'll see what happens... call the guy from aquarium design group if you have questions, he's super nice.