I recently moved to Thousand Oaks, CA and added a small pond with a black plastic liner in the back yard. Added a filter with a small fountain and a bamboo "deer chaser", then added plants (water hyacinths, water lettuce, a couple of tall grasses and a water lily.) I have stocked the pond twice with small feeder goldfish and both times the fish died. Now the floating plants are turning brown and slowly dying and the water lily has not grown. Our water is heavily chlorinated and I always added dechlorinator when adding water to the pond. I had a small pond at our previous house in West LA and the plants grew and the fish thrived. What could be wrong with my current setup? Any suggestions would be welcome