I honestly don't even give my plants any nutes period besides 1/4 veg until at least 2 weeks. Try and find a hydro store if you can and look for something called Pro-Mix soil. It doesn't come with nutrients in it so you can play around a little more without hurting your plants. It's about 30 bucks for 3.8cu ft and its perfect for dope plants.
Keep off of the nutes until you feel your stem is getting harder or not bendy anymore. That's my experience so far. Make sure you're not using ANY fertilizers if you are until a month into veg.