FFOF is fine for weeks without anything added. It’s actually a fairly hot organic soil straight out the bag. Just water your plants; that’s what you are doing wrong. No need to ph anything or check runoff.
Problem now is that you’ve likely rendered the soil a sterile medium with heavy nutes so youll need them to finish this grow. Give them just plain water for a week or so to recover. Leaves that are fried will die off; may not ever be green again. Dilute nutes to half strength and feed once weekly; twice if they seem to get pale....plain old water the rest of the time.