We need more info to give you correct advice. What nutrients, in what media? I assume you mean your nutrients are mixed at a rate of 7 ml per gallon. Do not cut this concentration if that’s what the instructions call for. Mix however many gallons you’ll need to water your plants. Mix what you need for the day in a drain to waste system or mix what you need for the week in a reservoir. Mix 7ml per gallon and feed them this concentration every feeding, no matter how many times a day/week.