Submersable Heater Melted.

Hi.

The submersable heater in my 75 gallon marine tank melted yesterday. It was
A VisaTherm from Aquarium Systems. I've had it for several years and have
never had a problem. When I got home there was an obvious oder that
something electrical had burned up. After verifying that all the
fluorescent lights were still running, I decided to check the heater. Sure
enough, the cap had come off and the tube was flooded with salt water. I
immediately unplugged and removed the heater. I've since replaced the
heater with a new one.

The temperature of the tank was 75F. All my fish were alive and do not
appear to be stressed. The few invertebrates I have in the tank appear
unaffected to. Is it possible for the heater that burned up, to release
toxic chemicals into my tank? If so what should I do? I always run Active
carbon in my canister filter, so it should absorb any contaminates released
by the heater, right?

Thanks,
Glenn