Planted Tank Enthusiast
Join Date: Jan 2015
Location: Carmel, Indiana
First thing I would do is add prime to try and get some of that ammonia bound up. My concerns about doing lots of large water changes is that if the pH of your new water is very different from your tank water, then you can cause more fish deaths.
If your new water and old water match up closely with pH and TDS, then I personally would do several large water changes, possibly up to almost 100% change. I would NOT do that if the new water parameters are vastly different from the old water.