Our pond was built last July. It is about 10X20 and about 2 to 3 ft deep. The sides are lined with big rocks. With a 2 ft water fall emptying into the pond. We have 7 Koe and about 20 gold fish but we seldem see them. They hide in the crevices of the rocks. What can we do to bring them out so we can see them? Does the water fall bother them?