The Puffer Forum

Hello all. First time posting and its question.

I have around 4 Green Spotted Puffers in a 75 gallon tank. I have had them for a year now and they were all fairly healthy. I have been meticulous about keeping up the quality of the tank and making sure I do 50% weekly water changes and keeping the salt/fresh water balanced.

Well, my oldest puffer who is the biggest hasn't been doing well lately. He is fairly big yet a quiet and docile puffer. I did a 50% water change and made sure I was sticking to my usually process. I noticed on Monday he started to become lethargic. He has a fairly black belly and his top portion is faded. He seems to be having trouble breathing. Save for sporadic instances when the bellies would change, I have never had my puffers change to black before. I read it could be stress but I have various places to hide, rocks, and fake coral (I can't afford live rock or coral).

He will occasionally hole himself up in one of the caves or hang out at the top of the tank, usually by the filter or the corner. I read the black belly is a sign of either stress or parasites. Aside from stress, is there anything on the market that can cure the parasites? Or is there anything else?

The other puffers are doing and eating fine; largely ignoring the big guy. My wife suggested a water change but I am not sure if that will fix the problem. No I am worried i didn't put enough/put too much sea salt in there.

Any thoughts? I am sorry if this was brought up before.

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Look up & answer every single question, please!

Yes please answer all the questions above in red so we can better help you. Welcome to the forum

Water changes almost never hurt, as long as you don't change the salinity by too much and crash the biological filter. Doing the tests above (especially ammonia) will tell you if that happened, which is why people tell you to do it

Is his belly sunken in, or still nicely rounded, just black. Can you sneak peaks at the tank at night and see if the others are harassing him when lights are off maybe?

Parasites can certainly be treated, but usually the fish will have a sunken belly. And its always risky, if they have a big load of parasites the die off when you treat can actually poison the fish, but that's pretty rare and if the fish had that many parasites in it, it was probably going to die a long, slow horrible death anyways. I would doubt that, after a year, you'd be first seeing signs of parasites unless you've recently added tankmates or feed live feeders though.