[Robert]

David i have made a hole slightly 2" above the base so there are always water held on the base. That keep the clay moist always. I water every 3-4 days and allow water to fill the top then let it drain off the excess thr' the hole.

Jeff, clay was collected from natural site. The minerals, acidic or alkaline, occured are natural occurence and will be very low in percentage. Thus it's doing well, i think so.