The Puffer Forum

Hi guys I'm hoping you can help, yesterday evening I came home to find my fahaka puffer had developed a black mark/smudge on his face just under his eye. The mark isn't raised from the skin and isn't a uniform shape and it has not grown or changed at all in the past 24 hours. I have tried to research it but the only things that I can find are ammonia burns and black spot disease but I don't think it's either of these.

He is feeding and acting normally, and as a bit of extra info, I posted a topic a little while ago about strange faeces he was creating (white mucousy film), he is no longer producing these but I still intend to treat him with metronidazole as soon as it arrives in the post.

I have attached some photos, apologies for the poor quality but hopefully they will help with diagnosis, any advice as to the cause of this black mark would be appreciated.

Thanks in advance

Tank Parameters:
pH 7.2
Ammonia 0
Nitrate 20
Nitrite 0
Tank size 106 litres 30"x12"x18" (he will be upgraded to a bigger tank as soon as possible)
Inhabitants: 1x Fahaka
Recent changes: fahaka was moved into his new tank approx 2 weeks ago
The tank has been set up for 3 weeks running on a mature Eheim 2217 filter which has been running on another tank for 2 years
Water changes: 45-60 litres per week in 3-4 installments

Could it be a burn from an unprotected heater?

Yeah I considered that, looking at pictures of burns though, they're usually white (?) and it doesn't look ulcerated or anything. Will pick up a heater guard just in case though

Add some Melafix & up those WC, to get the nitrate down <20.

Ok thanks for the advice, can I use melafix and metronidazole at the same time? Whist I have you guys, could you give me some further advice on using metronidazole please? I've read on this forum that you are supposed to treat the fish orally in it's food, will this treat any Protozoa that may be in the tank as well or should I treat orally and the water as well? Could you also confirm the dosage required please? Thanks guys and sorry to be a pain!

I have only treated for IPs internally.

What dosage is required orally? I'm getting 250mg tablets and he's 4-5 inches long

Just soak his food in 1 crushed tab. All food must be treated for 3-5 days.