update: After being belly up for 3 hours, he's now swimming around the tank again??? Definitely very stressed and ill and I'm not hopeful, but better than being upside down. First time I've seen him swim below the top water column in days.
History:
- 2 weeks ago I returned from a vacation to find I'd had a nitrate spike (80 ppm) while away. My puffer was breathing rapidly (100 per minute) and had some crater like holes on his body, with minor fungus.
- Dosed Expel-P in case of parasites, but I usually dose every 6 months. He started to become more energetic
- After a few days of rest from Expel-P, dosed lightly with Maracyn to help his skin. His energy was returning to normal, begging for food as usual. Added some VitaChem to his diet to help him recover.
- 3 days ago: As he dove for bloodworms, appeared to have buoyancy issues and struggled to right himself for about one minute. His energy started to decline and he'd stay near the top at a 45 degree angle, nose pointed towards surface. Increased oxygenation again.
- 2 day ago: Appeared to have a "seizure", for about 2 minutes went belly up curled in a c shape, breathing slowed. Came to and righted himself. Added PraziPro in case of internal parasites expel p missed. Swam in the light current of the airstone for the past 48 hrs.
- Today I noticed his coloration was much darker, but he was still swimming around. This afternoon I found him upside down in the floating plants, breathing at the same rate but with an obvious brown patch on his belly.
1) 0 Ammonia, 0 Nitrites, 5 nitrates
2) 20g, 3 endlers (no new tankmates in over a year). Lots of valisneria and anubias.
3) Primarily ramshorn snails, some bloodworms and dried freshwater shrimp as treats. Using Prime as conditioner.
4) No changes in the past year.
5) Stable and cycled for over 2 yrs, cycled using filter media from another established tank then adding ammonia drops until it could convert 2ppm ammonia in 24hrs.
I know it's likely too late at this point, but if anyone has any advice I'd be happy to take it.