I've used the following with good results.
2 quarts water, cold
3 ounces brown sugar
18 ounces kosher salt
20 grams cure #1
2/3 tablespoon onion powder
2/3 tablespoon garlic powder
1 1/3 teaspoons black peppercorns, whole
2 2/3 bay leaf
Stir all ingredients until salt and sugar dissolve.
Time in brine: Under 1/4 pound / 30 minutes
1/4 to 1/2 pound / 45 minutes
1/2 to 1 pound / 1 hour
1 to 2 pound / 2 hour
2 to 3 pound / 3 hours
If the skin is left on the fish then increase the time of brining by 25%.
or oily fish ( chub, herring, pompano, trout, whitefish, mackerel, kingfish etc...) increase time of brining by 25 %.
Overhauling: To obtain the best curative and flavoring effect all pieces of the fish must be freely exposed to the brine solution. Overhauling is simply the process of rearranging the pieces in the brining container to provide for a proper turnover. Overhauling is not necessary for brining periods of two hours or less.
Remove fish from brine. Rinse and pat dry. Arrange fish on oiled racks and all to dry until a pellicle forms on the surface, usually 30 minutes to 1 hour.
Set smoker to 150° with about 2 ounces of cherry chips. After 1 hour, raise temp to 180° ( try to hold 190°) and check filets after 1 1/2 hours.
Filets are done when they can be flaked easily with the tip of a knife or fork.
Fish is done when the internal temperature reaches 140°.
Weight of fish and Time to smoke:
¼ lb. To ½ lb. 1 and ¼ hour to 1 and ½ hour
½ lb. To 1 lb. 1 and ½ hour to 2 hours
1 lb. To 2 lbs. 2 hours to 2 and ½ hour
3 lbs. To 4 lbs. 2 and ½ hour to 3 hours