Many thanks for your replies.
I do water changes every week, along with vacuuming the gravel. The stats are fine as can be, tested em yesterday, nitrate and nitrite and ammonia at nil and ph has always been rather high ever since i've had the fishies and remains to be at about 8.
Its a 96 litre jewel rekord tank with plants and a gravel substrate. Inhabitants consist of 5 other corys now, 2 gouramis, 1 red finned shark, 5 panchax, 1 plecy. My panchax recently had babies but they have been put in a seperate tank now. All get on fine as far as i have ever seen unless they've got some sneaky thing going on that i dont know about! This tank has been running since November, which is when i got the new tank. Before i had a smaller tank and i transferred the gravel and ornaments from that to the new tank so cycling was speedy. I've had my albino cory since August time when he was a baby.
I'm pretty sure the deaths that occured to my dear corys were due to a power cut in the middle of the night, it was the day after it when my bronze cory, Watson, took a turn for the worst and then so did my other cory, Wibble, who i had to euthanise around Christmas which was an awful thing to do and i shall never do it again as it was so upsetting. I treated the tank during this time of illness with an internal bacterial meds but alas it didnt help.
When i put the new corys in last night it was lovely to see them all foraging around, a delight in fact. Really sets the tank off and makes it more cheery. When they do stop and take a breather they all group together, its proper nice to see. Al ( the albino) is still around. Still a bit odd in behaviour but i'm pretty sure he likes his friends. They can't get enough of him thats for sure. Been gathered around him for ages.
Anyway i think this is all the info i can give. I've just put some revitiliser tonic in to see if that perks him up.
peace out x
Going to have to ask lots of questions, but I am getting ready for bed. If no one else helps I will be back. Sorry about your losses.
Sad and lonely id possible, but the losses suggest that something else needs to be addressed. Cories are incredibly hardy for the most part. Try to put together the information you can think of that might be relative,=: tank maitenance schedule, tank size, and inhabitants, water stats, tank maintenence routine, length of time tank has been running, etc etc etc