Corleone
Fish Herder
Not necessarily, especially if it's a relatively low-level, long-term problem. The fish that are in the water will have adapted to the conditions and only be stressed by them, while fish introduced into them will be hurt far worse and may die quite quickly.
At least get a nitrite kit ASAP - ammonia and nitrite are the most critical water stats to monitor, and the most likely to give an indication if things go wrong.
At least get a nitrite kit ASAP - ammonia and nitrite are the most critical water stats to monitor, and the most likely to give an indication if things go wrong.