Why do i have high ph and ammonia levels in my fishtank?

ammonia levels can rise due to fish waste, so gravel cleans are needed every two weeks by removing 30% of the water at the same time. go to your local fish shop and buy some zeolite which you put in the tank in a net or place in the filter this will keep your Ammonia down, with Ph just add crushed coral which is good for keeping your ph levels right. good luck