Sue and Dingus,
Sorry, I haven't been available for awhile. Just getting back into the swing of things.
We used to recommend a lengthy acclimation. Interestingly enough, we didn't do this with new arrivals that we received, as everything that came in the building got a freshwater dip before entering our tanks. This got me to thinking and I started researching acclimation. I found that many did not recommend drip acclimation, rather equalizing termperature and immediately removing the fish from the bag. This list is lengthy, Fenner, Calfo, Bartelme, Michael, Stoskopf, Blasiola, Gratzek, USDA, University of Hawaii Sea Grant Extension Service, and I am sure I can find others.
When the seahorses are being shipped in a bag, they will give off CO2. This in turn will lower the pH in water. This and a low temperature in the bag will help lower the toxicity of the ammonia that builds up. When the bag is opened, the pH will begin to shift as the CO2 is expelled. Combine this with any warming of the water and the ammonia toxicity increases. Adding tank water to the bag only lengthens the time the fish are exposed to increased ammonia toxicity and increases the stress to the fish. They will have already gone through a temperature adjustment and a pH swing, a minor change in salinity is less stressful than the ammonia change.
According to Dr. Stoskopf extensive research shows that there is greater mortality with drip acclimation. We have found since we have changed our recommendations on acclimation, we have fewer issues with customers when they receive their animals. This includes a faster response to feeding after arrival.
Dan