Either is fine, as long as your ph is good. As your plants like a ph of about 6.6-6.8, but some strains like a different ph, depending on where the strain came. But that usually isn't the case. What strain are you growing? And water also depends on the plant. A good test is to stick your finger down to your first knuckle if it's dry it needs water. Also, get used to the weight of your plants before and after watering, and you'll get an idea of when they need water. Usually every 2-3 days, but that also depends on how big your plant and container are! Bigger plants require more water, and smaller containers dry out quicker! Make sure your pot/container also has good drainage as you don't want and water just sitting there, it can cause root rot (which is no fun). If the water isn't draining then you need more drainage holes! When you water you want to make sure it runs out through the drainage holes, that way you know that ALL of the roots are receiving water. Also under watering Is as bad as over watering, it's very easy to over water and it's not good. As it drowns your plant, and deprives it from oxygen, which is VITAL for you plants survival and photosynthesis. If your using tap water then try to let it sit out for at least 24hr with no lid or anything if it's in bottles so that any chlorine or additives can dissolve. How old is the plant? Have you started a nutrient program or going organic?