Quarantine of single tetra - & more general beginner quarantine question

hello! I got into the hobby over the winter so am pretty new to things, but eager to learn.
I have a 10g tank with 5 neon tetra from a shipment a month ago (was supposed to be 7 but 2 died in transport )
just got a second shipment with some plants and 2 more neon tetra to round out the school. I seem to be cursed - in the bag of 2 tetra, one arrived very dead (& partially decomposed/eaten? :-| ).
so the other living tetra is in quarantine now. my questions are -
- what do I look for? in general, and specific to tetra? (talking about after the first day or so when the shock of travel has worn off somewhat)
- if you were me, would you medicate by default? or just wait and see? what medication(s)? (I've seen the "quarantine meds trio" but would love to not drop $50 and pump my single stressed out tetra with a bunch of medicine unless it's important)
- how long? I've read everything from 2 days to 6 weeks... (would love for it to be shorter as there is literally no place for a second aquarium in our tiny boston apartment so the sooner I can pack it away the better for my relationship with my husband, haha)

thoughts are appreciated! thank you for your patience for these beginner level questions.

 

Neons tend to be a bit dull after long distance shipping so look to see if their colour gets more vivid in the qt tank ( usually within a few days) . Check that it is feeding well when you feed it. Look for any signs of growths especially around the mouth and the fins. Make sure it isn't sitting on the bottom and that it's swimming the right way ( not upside down or sideways or pointing severely up or down ).
If you don't see any symptoms I wouldn't add any meds.
Keep the water clean, if your qt tank isn't filtered and cycled change a third of the water daily with dechlorinated water.
If you don't see any signs of disease in 8-10 days I would say you could add the fish to the tank
If you are having a number of fish dead in new deliveries I would seriously consider finding another supplier. I have bought numerous batches from an online retailer in this country and only ever had one fish arrive dead.
Are you sure your main tank is fully cycled?
Do you test the water?

 

Thanks for responding! Sounds good - 8-10 days feels reasonable. He is a bit dull and hasn't been interested in food at all yet... but it's only been 2 days. I remember the other neons just hid out and also didn't eat for a few days (I would assume due to the shock of shipping). No other symptoms or weirdness.
I have had bad luck with two separate suppliers that both have great reviews - both had a "live guarantee" & offer refunds for dead or sick fish. obviously I would prefer the fish to be healthy & alive but it does show they care about their QC with that at least.
main tank is definitely cycled - heavily planted, waited months before putting in any livestock, no ammonia/nitrites on the strips. I check water parameters every day-ish and definitely every day around the weekly 20% water change. everything that goes in the tank seems to be doing well, that's why I'm paranoid about adding a diseased guy to my happy little land of neons and shrimp. the fish have showed up dead through shipping, not after they go in the tank. I wish I could find a good local fish store but the only one in a 30 minute radius is a petco currently renovating their aquarium area, thus extremely low stocking of anything living. hopefully this will be the last livestock purchase for a long time and I can buy locally next time I need to add anybody.
thanks again for responding! very good to hear I can quarantine the quarantine tank fairly soon

 

Personally, I do not believe in medicating unless you see a problem. Meds can cause stress...
I usually QT for two weeks. And I buy from a local store with very good stock (not a chain), so I am usually confident the fish are healthy to begin with.
If you buy from a chain, ask them what day they get their shipment. Then wait to buy the day or two before that. This gives the fish time to settle in to the store tank, and any fish who was going to die within a day or so of being shipped will have done so already. The ones that are left will be more hardy.
Just from my experience with chain stores! Good luck!

 

I need to find a local fish store that's not a chain. Like, for real. I'll ask around in the New England freshwater fish group. I can't keep dealing with this shipping nonsense - seriously stressing the fish, and super pricey!
Good to hear I don't need to medicate as a default.
The new neon is getting a bit more feisty today, eating some and dashing around a bit. I think he's probably fine? I'll watch him for another few days to be sure.