If you had used an organic fert to begin with it probably would not have hurt at all. My first grow was with a soiless mix that had plentiful goodies that I got from an organic nursery run by a pro gardener in her seventies. She has been growing since she was probably in her twenties but she mixes all her stuff and brews her own compost. The stuff is wicked. I still used Grow Big, Big Bloom, and Tiger Bloom. The plant was about five feet indoors at week four. It was a bad mamma jamma. I used a LOT of fert too. Nothing that was a killer but half a capful per 24 ounces so I guess it was about right from the directions. FOLLOW THE DIRECTIONS AND YOU WILL BE FINE.