so when i purchased my 75 gallon a while back it came with an aqueon stand designed for 75, 90, and 110 gallon aquariums due to their similar footprint. Every once and a while I hear a creaking noise coming from the tank area. Is this normal when new stands are adjusting to the weight? Also, sometimes when I am standing right beside the tank doing a water change the same noise happens. What do you think?