Tunze circ pump. In tank like 2.5 yrs (time flies!). Cleaned pump today and noticed visible wires. Has been cleaned only a few times - citric acid or diluted bleach. Don't remember overscrubbing it in the past and today used soft toothbrush. It is right near the pump, always submerged. Could urchins do this? A pink pincushion one definitely goes on the cords. I can ask students next week if they have noticed the wires showing. More importantly, what can I do to fix it??? Wrap it with something? Seal with some sort of aqua safe silicone? Wires inside appear to have all insulation. I turned it off for the moment, but this is an expensive pump that works great and I need it back in operatio n.