gouramigrl, your 2 gal tank is practically useless for fish. 1 betta might be ok in it, but it's pushing the minimum.
something you should consider is that many creatures can survive in an environment not suited to them. but they can't thrive in it. for example, you could survive in your bathroom for your whole life, provided food..but what kind of a life would that be. that's the type of thinking that goes into the size of tank a fish should have.
in the link you posted, it says glass catfish need 100L tanks. that's about 25 gallons. also they should be in groups. yours might be alive and seem fine, but they will probably live shortened lives. also when you give a fish a tank that is really big enough for it, you'd be amazed how much different they act and how much more enjoyable they are to keep.
tell us what fish you will have once you are done giving them back to the store.
you should definitely consider getting a 20 gallon tank instead of your 10. it gives you many more options for fish you can get.
also its very likely that those other cory's you had died because of the tank being overstocked and not cycled at the time.
how long has the tank been running now?
My 2 gallon tank surves its purpose its for keeping the males away from my females, ive been breading guppies in this tank for about 1 year now and i do realize my 2 gallon tank is overstocked but it was not over stocked 1 month ago when all my guppies were fry! so thats why im getting all my guppies a new home in someone elses fish tank.
as for my glass catfish they thrive best in a single species tank but if you go with everything you read you might as well get a whole apartment full of 20 different aquariums. they are best in groups and i havent ever had them solo and they are an interesting fish to study if you feel you would like to keep some then i suggest you get 3 or 4 and place them in your tropical community they do not need anything other then a few plants they are peaceful and hunt for there food. they have been in my tank since it started.
as for you commenting on my cory cats dying because of my tank not being cycled. your way off track. i cycled my tank with a betta and a couple of guppies before adding any cory cats and if my tank was not cycled my glass cats woulda been the first thing to go due to there really sensitive immune system. i purches my glass cats to go with my betta and guppie's and then purches a couple of albino cory cats for a clean up crew. and had that tank running for a full 6 months before i messed with any of the fish inside other then regular maintence.
i then sold my guppies and started breeding my own. and purchased a golden dojo loach/weather loach and he lived full grown in my 10 gallon tank with my 2 glass catfish and my betta for another 3 months. and then i let my boyfriend put him in his cichlid tank and he ended up getting very beaten up and eventually died. which gave me the option of getting other fish. i sold my betta and purchased a gourami. and a few julli cory's and the julli's did not live very long about 1 month i think it was just a bad batch.
tank from cycling point until present day has been running for a little over a year!
sorry for being defensive in this reply but i felt attacked as to you making me out to be a dumb a$$