ANOTHER panda down!

[saphphx]

So went to the fish room to feed the little dears, and one of my little pandas was swishing about and kept falling on his side. This tank is on a different floor and has its own set of kit and is no way related to the other tank I am having problems with (here: http://www.planetcatfish.com/forum/view ... p?p=111343) so I am quite confused and depressed with it all. His tank mates are bopping about like happy bunnies, and this morning he looks better, swimming some, and not on his side at all. All I did was give him a half dose of tonic and move him to his own tank with a sponge filter and some java moss.

The Sick Fish
Species: Panda cory
Size: less then an inch
Food: sinking cat fish food, frozen foods
Feeding times: very small amounts in the morning, afternoon and evening.
Normal Tank Mates: 8 other panda corys, 5 albino bronze corys,
Water parameters
Temerature range: 75F
pH: 7.4
GH: no test for this - its on order
KH: no test for this - its on order
Ammonia: 0ppm
Nitrate: 0.4ppm
Nitrite: 0ppm
Water change frequency: 25% once a week
Tank set up
Size: 36x12x15 inches - 99 l./22 gal. (26.15 US gal.)
Substrate: Sand
Filtration: Fluval 4+
Furnishings: Slate caves, castle, little plant pots
Other tank mates: 6 albino bronze corys, 3 schwartzi corys, 8 other panda corys, 2 normal bronze corys, 2 hillstream loaches on the 31st of March 07
How long has it been set-up? over a year now
When was the last new fish added? hillstream loaches 3 weeks ago
Is there a heater in the tank? no - room is heated
Symptoms / Problem description: went in to evening feed and he was swishing about in his side.
Action taken (if any): removed the fish, put him in a 10ltr tank, treated with tonic and used aged but clean water.
Medications used (if any): 1/2 dose of liquasil tonic
NEW QT Tank
Size: 10ltr
Substrate: none
Filtration: sponge filter
Furnishings: java moss to hide in
Other tank mates: none

Any ideas? I'll be doing a water change today just incase my test kit is off, but just had this fight with the LFS, and discovered THEIR kit was off when I took mine in, both tested the same water with different results, then they opened a brand new kit and we got the same results, so did another new kit and had the same again. (Moral: sometimes the shop is wrong )

[saphphx]

Unfortunately during the morning feed he looked fine, though on closer inspection he was actually still upright but dead. So I am guessing when he "looked fine" last night (I know they often die "standing up" but I hate to poke them until they haven't moved in some time as it just stresses them out) I would expect he had already died, even though I swore I saw him swimming normally before feeding him in the evening.

Hopefully the other cory will do alright. He looks loads better this morning. Actually swimming and fighting off the bigger corys for food lol!