my spiny puffer has puffed up twice in the past week. i have read that it is bad for them to puff up. there hasnt been any new members added to the tank or any changes at all. is there a problem or do they just do that every once in a while

no idea...... at my lfs they puff up when they are pissed or scared. Try to catch him and he will get scared WAHHHH puffed up. crazy cool. But I wouldnt think its bad...maybe you startled him when you walked by. He could be jumpy still in new surroundings.