My corydoras arcuatus !!!! finally

Oh sorry. They look so cool in the first photos. Keep at it though and I would definitely try to get them from a breeder.
 
So sorry :( Was your tank new? I noticed how sparkly clean it looked.

Wild caught fish usually need a "seasoned" tank to do well, in my experience - I don't know what it actually is because in theory, you should be able to keep sensitive fish in really clean water of the right chemistry, and that should be the only requirement. But emperor tetras, for example, don't do well in brand new tanks even if you check the water quality often and never let nitrates get over 20 ppm. There's more to it than that, but I guess ordinary hobbyists will never have the testing equipment necessary to measure anything besides the basic water quality and chemistry parameters.

Perhaps all that's necessary is a seasoned sponge filter in there?
Yes, that's what I was thinking. the tank was like less than two months running. So I guess it wasn't very well "seasoned". On the other hand my 29 gl is been up like 2 years already.
 
Sorry the four did not make it - how is the last one doing in the 29g?
 
Sorry the four did not make it - how is the last one doing in the 29g?
The last one is doing GREAT!! in the 29 gl. I was afraid it was going to be lonely. It's all the time looking for food with its buddies (5 corydoras schwarzi) all over the tank. Still I thinking to get him 5 friends of his own species.
 
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