The easiest way to reduce toxic ammonia buildup in transport water is to lower the temperature of the transport water and to stop feeding several days before transporting. Fish up to 8 inches should not be fed for 48 hours before loading and transporting and those larger than 8 inches should be off feed 72 hours before transporting. Chemical Additives Numerous chemical additives can be added to the transport water to alleviate several problems associated with transporting fish in sealed bags. Because overdoses of chemicals can result in death, care must be taken when measuring the dosage of each chemical used. It is essential to double-check every calculation and to use an accurate balance before adding chemicals .
Salt is used to relieve stress associated with maintaining a water balance in the fish.
Fish have a blood salt concentration higher than the salts of the transport water. Canning salt is a good example. If the water alkalinity of the transport water is less than 100 ppm, some type of buffering compound should be added to the water. Finally, because fish are transported in crowded conditions, stress will be placed on them. Sometimes a chemical anesthetic may be beneficial by producing a light sedation.