Cell Sparking

I have a Zodiac Clearwater LM2 SWG that I have had for about 2.5 years now.

Tonight, for the first time, I noticed that when the cell is operational, there is occasional arching from inside the cell producing a visible flash.

Is this normal, or the sign of a bad cell?

WOW...it's not normal.
Are the blades close together? I can understand that if the blades are closer together than normal, that the electricity may arch from blade to blade, rather than conduct through the water, which is what it's suppose to do.