would it help to make your own:

1 teaspoon baking soda
2 teaspoons cream of tartar
1 teaspoon corn starch (optional)

Mix the baking soda and cream of tartar together until well combined. Use immediately.

1/2 cup of cornstarch
2 egg whites
1/2 tsp of white pepper
1/8 tsp of ginger
A pinch of salt
Enough liquid to make a thick pancake consistancy.

I have used water, beer, pineapple juice, apple juice, orange juice, cranberry juice, what ever suits you and what you are going to fry.

For fish I would just use water and after frying squeeze on some fresh lemon juice.

This batter is the closest I have come to the crispy batter used in most Chines food establishments.