Quote:
Originally Posted by denny@concept
amonia in salt is quite common as an impurity 
from RHF:
There are a variety of sources of ammonia in reef aquaria. Minor sources include: 1) tap water (especially if it contains chloramine and is not treated with a deionizing resin) and 2) impurities in salt mixes and other additives. It has previously been shown that the total NH4-N ranged from 0.55 to 11.9 micromole/kg (0.008 to 0.17 ppm total NH4-N) in an analysis of eight brands of artificial seawater mixes. At the higher end of the scale, those levels will be detected with an ammonia test kit and can present potential toxicity concerns if fish are kept at those levels (see below). These levels of ammonia may be introduced from impurities in calcium chloride and magnesium chloride, where ammonia is a well known impurity resulting from some of the commercial manufacturing processes used (such as the Solvay process, which involves ammonia).
Calcium and magnesium additives can also be a significant source of ammonia, especially for aquarists who are trying to use inexpensive sources of bulk calcium or magnesium chloride. I discussed testing calcium chloride for ammonia in a previous article. |
This is all very true. But if you have a well established tank, the nitrogen cycle will quickly digest and render a small amount of ammonia totally harmless when added to your tank. But if it is accompanied by other deaths (eg livestock) and lack of O2, then the ammonia can indeed be a problem, and can result in what we call a tank crash.
Don't know if your problems were directly related to the salt, but I wouldn't take a chance with it, if indeed that was the only actual change to your tank routine. Best of luck with your recovery.