I have rays with sand in both my 480's and have noticed no scratching at all. I believe it could occur, but would guess what you are dealing with is some type of stress cracking, especially if all scratches run in the same direction. I can't see rays scratching acrylic in only one direction.
Stress cracks could be from an unlevel tank or from poor quality acrylic. If it's the acrylic, I'd complain to Tenecor. I had a 300 gallon from that at one time and they are not cheap. A 450 must of cost a lot and should be developing cracks.
Good Luck.
Pat
Stress cracks could be from an unlevel tank or from poor quality acrylic. If it's the acrylic, I'd complain to Tenecor. I had a 300 gallon from that at one time and they are not cheap. A 450 must of cost a lot and should be developing cracks.
Good Luck.
Pat
