It really depends on the plant. The dilution rate (for outdoor plants) is 1 tablespoon of Miracle Gro per Gallon of water. At this rate, for basic flower and vegetable plants, 1 gallon will cover 10 square feet.
Reusing greywater- it's touted as being environmentally-friendly, but it's actually wallet-friendly too. It can also be used to flush toilets. Just pour a bucket of greywater into the bowl, and the...
because with too much water, oxygen travels less easily around a plant. so whether you water it way too much or not at all, its either getting no oxygen, or no water