it's not a clay pot, it's a 3.5 gallon plastic one, with a separate drain tray. oh and it's not expert gardener soil, my bad on that, it's some other brand, i'll have to go back and remind myself what the name was. i checked the bag for anything resembling an npk level, there's nothing on there. last night i started feeding 1/4 strength schultz nutes. the water with the nutes had a PH of around 6.8. i watered til it started to drain out then checked the PH of the run off which was around 6.6. use tap water? why would you say to use tap water, i just mixed some "drinking water" with some "spring water" the drinking water had a low ph level, just the opposite with the spring water, used about 2 parts drinking to 1 part spring and it brought ph to around 7.0, and when i added the ferts it brought it down a little more, around 6.8, what would the benefits of using tap water be?