You have a new tank and there for your gonna go through the new tank syndrome!! When first setting up a tank you should let it run for a month before adding fish! Around the second or third week the water will get cloudy and then clear up after that happens its ok to add fish! I bet if you check the water the ammonia is through the roof! Its from the bacteria working through the tank! The only prob with changing the water before it goes through its cycle its like pressing the reset button on the computer its gonna just keep cycling! I'd let it run its coarse!