In a medium pot combine water with lemon and lime rinds. Try to exclude as much of the white pith as you can as it will make your soda bitter.
Cover pot and bring to a boil. Reduce heat and simmer 5 minutes.
Remove from heat and add sugar, salt and the juice from the lemon and lime.
Strain mixture and cool completely.
Add ginger bug and seal in either recycled plastic soda bottles or glass bottles with swing top lids.
Allow to ferment in a warm place for 2-3 days. Soda will be ready when you see bubbles forming on the top--this can take up to 6-7 days if temperature is cool. Burp the bottles by opening them to allow built up carbon dioxide to escape. Chill before serving and be sure to burp the bottles each day to release gas. Soda will become less sweet the longer it sits.