Dogface puffer

Question
Good morning,

I have a dogface puffer that has been in my 120g tank for approximately 6 months. His tankmates are a huma huma and a small three striped damsel. The puffer is by far the most docile. About a week ago, I installed a protein skimmer, and while doing so, realized my salinity had risen to 1.028. I did a 5g water change that evening, another the next morning, then again that evening. Prior to this my puffer was doing fine. Two days later, I did 15g. My salinity is now at 1.023. Since this activity, the puffer has been hiding or hanging at the intake of my wet dry, and not eating at all. No sign of external parasites. This has been going on for about 3-4 days. Last night he seemed to be out and about a little, and this morning he was in his usual place as if he was waiting for food, but still will not eat. I have heard the puffers can go long periods without eating, so should I not be worried? The water is all within good parameters and the huma and damsel are fine. My gut feeling is he just got stressed from all the activity and went on a hunger strike. Thank you for your suggestions and help.

Answer
Hey Randy,
Changes in specific gravity can have dramatic effects on our marine pets. The Dogface Puffer, Arothron Nigropunctatus, is one of the more common puffers in aquaria, but also one of the more fragile(very sensitive to his water chemistry). And you are correct, Puffer fishes are known to go on feeding strikes after a stressful event. If he goes beyond a week of not eating, you can try coaxing him to eat by soaking his foods in a little water and garlic for 10 or 15 minutes before attempting to feed. That has always done the trick for me in the past. What is the normal sg of your system? 1.023? If the swing in sg was a gradual climb, then the rate at which you reduced should have been fine, and the poor guy should resume normal activity and behaviors soon(5 to 10 days). If the swing in sg was a sudden spike, there can be damage to gills, internal organs etc. This is a rarity. I would say that if hes starting to act his old self you have nothing to worry about. It can just take several days to alleviate the stress of the changes in water chemistry. Just watch him for eating habits, change in gill coloration and any swelling. And keep offering him a variety of foods, give the garlic soak a try. He'll probably snap back soon. Let me know how it goes or if I can help!