HELP!!! Things are going sideways and bad!

[ScubaSteve]

Alright, So I got home this afternoon after picking up some frags to find that my HOB filter isn't running water. I guess the motor jammed up and I don't know how long it has been sitting like that. When I popped the top off to look inside, it smelled of hydrogen sulphide (rotten eggs) and the junk which normally accumulates in the filter (usually looks greyish) looked black. Bad, bad, bad, bad...

I am guessing that with no flow and an overheating motor the crap in the filter when anaerobic on me.

I ripped the thing off the tank right away (making sure not to get any of it in the tank), gave it a serious clean (we're talking spotless...), threw away the sponge and bag of carbon and replaced them with a new filter sock of carbon and some filter floss to replace the sponge.

Just tested the water:

Ammonia: Less than 0.25 ppm but greater than zero
Nitrites: 0 ppm
Nitrates: 5 to 10 ppm (looks closer to 5 ppm)
pH: 8.0
Salinity: 1.026
Phosphates: 0

Doubled checked everything.

I'm heading off to my lab now to pick up more water to do a serious water change. Does it sound like the filter just when anaerobic from no water flow? Is there anything else I should be worrying about?