hey daylily we are here to help you. i also come from an outdoor garden as well as hydroponics background. im also an experienced aquarium keeper but first time planted tank keeper. ive learned alot from this site. with gardens it is better to under fert then over fert, its true. and ph around 6.5 helps nutrients not get locked out by salt build ups. but in a planted tank, its ok to over dose as long as you do your weekly water change. i find in my spec v with stock light that dosing is not necessary but with certain plants may need certain requirements. try posting some pics others will come in to help.