Lone survivor now lethargic, maybe sick

[SpongeFilter]

7.4 pH, 0 Ammonia, 0 NO2, 20-30 NO3, don't have a hardness test but very hard well water. 20L, planted tank.

 

Had 10 guppies and a dwarf gourami and 2 Amano shrimp. I think 3 weeks ago, I had ich and fin rot. I treated for ich, couldn't get erythromycin in time. All but 1 guppy died (shrimp are just fine). I was sort-of depressed about it so I started a quarantine tank. 

The problem: now that 1 remaining guppy was just sitting on a plant this morning. He was upright flapping his fins, and he perked up when I turned on his light. I turned it back out and worked out for an hour. When I turned it back on, he was just laying on the bottom. Again, he perked up. I fed him. He started swimming around. I think he ate. His fins seem fine.

I might move him to the quarantine tank and hit him with the 5 day ich and erythromycin plan. I can't find general cure anywhere locally so I guess I'll order it and hope he doesn't die before it gets here.

Couldn't get a decent picture. Here's the best I could do.

[Cory]

In the picture it doesn't seem to have any ich or bacterial infection.  If you were going to quarantine. I'd use salt. But I'm not sure it needs it at the moment. Hard to tell from 1 picture. 

[Ben Ellison]

My guppies especially  the very pregnant females often lay on various  things with the lights out. I suspect  it is just sleep/resting and its perfectly  natural. If its eating well and pooping like normal I think you are good 👍