tank got wiped out.....

They dont use Hg anymore in thermometers, unless it is a really ancient or an expensive scientific model. Call the manufacturer of the hydrometer, the red alcohol mix in it might have just been as toxic.

What brand was it btw?
 
You wouldnt happen to mean Thermometer? i didnt know the hydrometers had mercury,or was it one of the ones with a thermometer?
 
I'm sure it's a floating hydrometer...it may include a thermometer, as well. If so, then the red alcohol in the thermometer may have killed everything. If it was just a hydrometer, it would either use lead shot or mercury to weigh the bottom down. If it had mercury in it you will definitely will want to call someone to clean it up.
 
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