I have a Oscar fish that i purchased from my lfs. He is about 6 inches. Every time i walk near the tank he swims away and hides in the corner. Im wondering if this is normal. The tank is fully cycled. .25 ammonia 0 nitrates 10 nitrites. The tank is running a fluval 406 and an aqueon 55/75 hob. The temp is steady at 78. I have 3 tanks all of them are reading .25 ammonia with the api test kit. I'm using seacham prime dechlorinator. So not sure if its a false reading or not. I've had this fish for 5 days.