Originally Posted by User24

since there is a problem, I would recommend starting with some soil mix from a store. it is not usually a good idea to bring dirt out of your backyard into a grow, as it can harbor pests and diseases. there is plenty of good advice on soil mixtures in the GROWFAQ Indoor Soil
you might also want to buy a cheap ph test kit (possibly on ebay or the paper strips from local hardware/swimming pool or hydro shops.)
tap water PH can be way out of step for proper soil grow, and that can cause all kinds of nutrient lockups and problems.