u/puffercrazy

Hi! I have had Amazon puffers fir over 3 years now and they still glass surf, I have tried everything to stop it, my tank is full of hiding places, the water quality is good, I have changed the light to a dimmer one. I think I have fixed everything that might be stressing them out but they still continue... Does anyone know what I am doing wrong. It really upsets me that they glass surf, any advise?