Dear Maxine, Because the Crocodile Isle water park features a large splash area, it would likely take several thousand playballs to fill it. Unfortunately, we don't have any information on how many playballs are shown in the photo. I would recommend starting with 900 ball pit style playballs, adding more later per your preference. In general, anything more than 900 balls becomes a bit of a chore to clean up. I hope that helps! Sincerely, Blast Zone Support