Quote Originally Posted by bondstreet
clay balls will have little or no effect on you ph unless they have salt build up on them
Fresh unused clay balls right out of the bag MUST be pre-soaked with pH adjusted water until the pH stabilizes. They WILL cause it to rise over the course of even a few hours until it is stabilized. This process can take a few days and should be done before living plants are introduced to the system, if you want them to stay that way.