Something Wrong With My Panda Cory?

Hi all! apologies if this isn't a genuine emergency but im concerned about one of my new panda corys which I bought just under a week ago. I got four of them but over the last two days I have noticed one of them seems more lethargic than the others and hides more often and has also exhibited what I thought might be a sign of early tail rot (see attached pictures). i am wholly unsure what is wrong though as I recently lost a five banded barb to what I thought was tail rot but saw no response to medication whatsoever (in a hospital tank).
 
My water parameters as of half an hour ago are: pH:7.4, ammonia and nitrite: 0ppm and nitrate: 40ppm (doing another 20% wc tomorow).
 
If anyone can help me diagnose what may be wrong with this lil guy as soon as possible id be very very grateful as I get really torn up losing them.
 
not sure how relevant this is but its a 110l aquarium also stocked with 2 glowlight tetras, 1 snakeskin barb, 1 peppered cory, 1 bronze cory, 4 panda corys. low numbers i know but shoals suffered attrition while i was at university for four years.
 
Thanks again for any advice on problems and hopeful solutions!
 
p.s. apologies for shoddy imgs but its the best my phone will do up close

oh and i should add that he is eating normally. only emerges for food at the moment

does anyone have any ideas what might be wrong? the redness has gone from the edge of the tail fin today but there seems to be a very fine opaque white edge to it instead which i thought was a fin rot sign? it seems to have a couple of other white areas on its fins which look like identical to the grains of sand in my tank but appear better attached than sand could ever be. not a chance of white spot is there?
 
would really appreciate any input as im terrified of losing another fish

With something that is not obvious I would use a general tonic, if you are in the UK I would recomment Esha 2000 - it is really good. It maybe just the pictures especially the second picture makes it look skinny, is there any signs of stringy white poo at all? I dont know why but my first instinct was an internal parasite infection, these can give secondary infections like fin rot, ich etc simply because of the second pic, if they are not skinny or have white poo then back to first suggestion of an antibacterial treatment.

It looks skinny to me too, what are you feeding it?
I'd suspect an internal infection too from the pic but the redness could be just from the lighting, can you get a pic where it doesn't look so see through?

thanks for the responses.
 
i feed them hikari sinking wafers and hikari algae wafers alternating each day and they also hoover up any tetra flake, hikari micro pellets or bloodworm i feed to the others. they are still very young fish with this one being only 2cm long.i have seen him eating a few times over the last couple of days though. should i just up the food to make sure?
 
i havent seen any white fecal matter no but its hard to with the sand below.
 
the redness has completely gone from the tail fin today and now only a very fine white edge remains. there are small growths on its head now too which have a cotton-wool-ish appearance which are relatively small. i have taken more photos (again blurry as too close for my camera but no good any further away) in which you can just see the white growth on the black head band and top side of the dorsal fin and also the frayed looking tail. all other fish in the tank seem perfectly fine at the moment too.
 
thanks again!!
 

The cotton wool like patches suggest a fungus or columnaris,I would quarantine & treat him.
Corys aren't algae eaters so the algae wafers won't be giving them much nutritions, I'd stop feeding those & just use the sinking catfish wafers.

ah ok ill stop with the algae ones then. would the esha 2000 be a good choice? or is there a better med like melafix etc? i have a 20l hospital tank so will do that asap

I'd go with the Esha, let us know how he gets on

ok will pick some up tomorrow morning! thank you so much for the help. will keep you posted! i saw esha is a 3 day dosing medicine. does this mean after three days i then leave him in there for a few days after all symptoms disappear? or do i keep dosing on additional days after if syptoms havent gone after 3?

You can use esha for 3 days and leave him in the hospital tank until he is clear, if he is not improved after the 3 days you can continue half dosing. I would recommend also using an anti internal parasite med, but on the whole tank, but with the feeding it maybe that is why he is skinny not worms. Try soaking their food in Vitazin made by waterlife, this will give him extra vitamins to help fight the infection. JMC catfish pellets and tetra prima are also good for corys.

have just given him the first dose of esha in the hospital tank so will keep you posted over the next few days. will also look out for some of those foods for the catfish. can you recommend a good anti internal parasite med? and are they generally filter, plant and snail safe? i have three nerite snails which i have had to remove before for a copper medicine and just left in room temp water
 
edit: should i also wait until i get the sick panda back in the main tank to medicate that one for parasites? wouldnt wanna mix meds in the hospital tank i thought?
 
thank you again so much for the help!

hey guys. day three update on the panda cory.
 
about half a day after the first dose all visible fungus had disappeared from the cory. however, now on day three it seems to have come back in even greater amounts - actually some of it even looks like loose bits of flaky skin tbh. the fish is breathing normally but hasnt eaten anything since it went in the hospital tank and also doesnt move at all except for when the current pushes it around. have attached some more jpgs. any ideas??
 
thanks a lot!

To me this poor fish is too far gone. I'd euthanise it (sorry).

it seems it was yes. poor thing passed away during the night dont think i ever saw myself getting so attached to fish when i started this hobby but its bloody hard losing them
 
how typical is it to lose one from a new batch of fish? this seems to happen to me every time i get a new group about a week or so after introducing them despite constant monitoring of water conditions etc to minimise stress levels and any chance of bio-overload. i cant quarantine yet either which i guess doesnt help but my lfs is well set up with no central filtration etc and i check thoroughly before buying.
 
thanks again to everyone who tried to help. if nothing else then losing fish just educates me further for the future!

Don't know in what country you're living, but in Europe especially ijn Europe lots of Pandas are bred in the Czech Republic and arrive in the LFS very young (too young ???) and in a very poor state (underfed aso).
Therefor they are very prone to all kind of infections aso. Beside of that they are often (even in the LFS) on a wrong diet.  They are mainly carnivorious and will start to have problems if given too less protein (especially young Corys).
Noticed the lack of protein at certain stages of their young life can cause irreversable damage to these beautiful fish.