hi , i'm new in this forum , i'm italian , so sorry for my english :D i've bought a new carinotetraodon travancorius (pea puffer) for my planted 5 gallon tank , the puffer is in the tank for 3 days and is always hidden and shy on the back of the tank. water parameters : ph 8.1 no2 0mg no3 0.2mg cond...