I don't how much is 8oz water.I give 1 lt of water to 3gallons pots in week 3 generally.And nutrients,yes they are important to keep the plant healthy and happy.Happy and healthy plants reach their potential.If it's an average or high yielder,you can achieve what you desire with correct nutrients.Light is the main source for mj.good soil and nutrients make it to next level,environmental conditions are very important too.There is not a order in these,all of them should be sufficient for optimal results.But please do not buy too many bottles.They want to sell you but trust me most of those are waste of money. a good NPK base nutrients + some calcium/magnesium supplement + PK Booster in flowering will do the job most of the time.You can always add root accelerators for early veg stage and first weeks of flowering and some enzymes from veg/flo switch until last 3-4 weeks of flowering.In your further grows,you can even mix bat guano into your soil.These are the things to experiment and learn.And training of course.train your plants to make them get the light better.All of this will end up in some very good harvest.good luck