What pushit said. Most people want to feed their plants because they think it will make them grow bigger and stronger faster. If a little is good then more must be better, right? In reality, less is more especially when you are starting out. Knowing how your particular strain responds is as important as anything else. This is even more true when using FF or some other soil with nutes already added. Look, the company wants you to use their nutes right? The more you use the better it is for their bottom line. I start with 1/8 recommended strength and move my way up to 1/4 watching how the plants respond. Watch for a white tip at the end of the leaf. This tells you that the plant has reached their limit. But again, if you are using FF, up-pot on a schedule every 4 - 6 weeks and nothing until flower.

With the FF the most you will really need is a bit of Phosphorus and Potassium boost in flower, week three / four as pushit noted.There are some caveats like the fact that strains vary in what they like / can stand or that grow style (organic vs. non-organic, dirt vs. hydroponic) does alter some of these variables.