first time fish owner, have questions

Question
Hello,
I am a first time fish owner and have some questions and concerns.  As a gift, my children bought me a 29 gallon aquarium complete with several chemicals, decorations, etc, for a puffer fish, which I have always wanted.  The fish is green with black spots, a small (perhaps called dwarf?), and it is a brakish water fish.  We prepared the tank as we were told, putting in the necessary prime, neutralizer, and the Ocean Salt to make it brakish.  We have tested the levels and everything seems as it should.  About 5 days after the tank had been done, we bought the puffer.  We acclimated him to the brakish water (he had only been in fresh at the aquarium store) over a period of 40 minutes, as we were told to do.  That night he seemed to be fine, he was friendly, just like all the puffers I have seen before.  Then, that same night, we saw something coming out of what must be his anus...it was a very long white strand, with about 5 little white ball-like things on it, it grew several inches before it finally passed, afterward the puffer seemed very anxious suddenly, as if he were about to puff up.  We worried that it could have perhaps been eggs but upon speaking to the aquarium workers, who told us that puffers do not breed in captivity, we decided it was probably something he had eaten.  However, the day after, though he seemed and looked healthy he was not social whatsoever, never coming around to look at us, he would only stare at his reflection or go inside the little castle we put in the tank for him.  As the days passed (I would say it has been just about a week that we got him), we noticed a few worrisome things, including that he looked like he was graying very much, and that he spends most of his time in the little hole in the castle as if he is hiding.  We were told to feed him both blood worms and snails, we did blood worms (frozen) and then the following day gave him 2 snails, the size of his eye like we were told. Finally, we became more worried, as his coloring seemed grayer.  Last night my daughter took some of his tank water down to a different aquarium store in our area.  That aquarium told us, in as polite terms as possible, that the aquarium we had gotten the puffer (and his snails and everything else) was not exactly a good place, which we had already suspected after we found conflicting answers among the workers there as well as hostility.  The new aquarium tested the water, found that everything was ok, though apparently the phosphate level was high, for that he gave us a phosphate pad to put in the filter.  He said that coloring of the fisnh and his behavior sounded like a parasite, and gave us something called Metronidazole, with the instructions of adding three (one for each ten gallons of water, rounded from 29 to 30)level spoonfuls, every other day, with a total of three applications.  Last night we put it in, and tomorrow we are due to put it in again, then on Friday.  He told us to take out the pad in the filter because it could suck out the medicine as well, which we did.  Then he told us to do a tank change after his treatment, this weekend.  Today and tonight we have watched the puffer, he was very gray last night and we feared he would die.  This morning he looked a bit better though he spent his time mostly in his hiding place. Tonight he again looks very gray, and we are very worried.  We are concerned that the aquarium we got him from was a poor place, and that the fish is very sick.  We have never before had a fish, and have done everything we have been told, but still we have a graying, very unsocial little puffer as oppose to the happy, green and extremely social fish we have seen before.  Can you please tell me what you think the problem may be and what we can do?  I know he has had only one treatment of the parasite medication out of the three, but shouldn't he be doing better by now?  Why is his personality so different than any we have seen..is it because he is sick?  Also, we removed the snails and have stopped giving them to him, as we worried that as they were from the same aquarium they could be sick or have parasites, for the past two days he has only had bloodworms, we give him just under a quarter of a cube as we were told.  Are we doing something wrong? Any help you could provide us would be so very appreciated, at this point I am worried that he will in fact die, and I have wanted a puffer for so many years.
I apologize for the length of this letter, but I wanted to make sure you knew exactly how we have done things in case we made an error along the way.
Thanks again so very much for any help you can offer!
Very Sincerely,
Barbara (in Connecticut)

Answer
Hi Barbara,
 Your little puffer has an intestinal infection and had it when you got him.  The white stringy feces with bumps in them are a dead giveaway of an intestinal infection.  The medication might help but fish medicines seldom work right away and it might be some time (days or longer) before you notice any improvement in his behavior. Sadly, with this sort of thing it is a bit of a race between the time it takes for the medicine to clear him of parasites and his ability to last that long.  From your message, it sounds like he is still eating, which is an excellent sign and greatly increases the odds of success.   

 Be sure that you do not leave any food in the water that he does not eat right away. That will rapidly foul the water and cause further problems.  

-- Ron
  rcoleman@cichlidresearch.com
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