The only things you need to remember to do when mixing salt are:
-Use a dechlorinater
-mix it with water in a bucket first and let it dissolve before you add it to your tank, adding salt straight to the tank can cause burns on your fish. So mixing it in a 5gallon bucket with a heater+power head is a good idea.
-Only raise the s.g. by 0.002, that way you don't kill off the bacteria in your tank and cause a mini-cycle, there's no need to remove media or change anything with the filter, the bacteria can adjust to a small increase in s.g.
-Keep an eye on your levels, and if you need to, do another water change. It's better to be safe than sorry. If it spikes, or even rises by one or two, do another water change.
Glad to hear everything went well and your puffer is happy
