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Losing corydoras :-(

Subject: Losing corydoras :-(
by georgep56 on 2018/10/20 8:21:26

Hi all,

Over the last number of days a number (2-3) of our peppered and panda corydoras have died, and this morning another one is lying very lethargic at the bottom of the tank, alive but only just

All of the other fish in our well-established 120l tank (various barbs and tetras, albino corys, shrimps...) appear to be fine and active, the water tests (ammonia, nitrate, nitrite) are all spot on (I have been doing regular water changes).

It appears that *something* is affecting just the corys. The ones that have died have had no visible marks or scars anywhere and no other effects such as bloating and the 'only just alive' one, apart from having its fins closed down, appears visibly OK. I am attaching a photo.

If anyone could suggest anything I'd be really grateful; the only thing that comes to my mind, having racked my brains, is the slight possibly of overfeeding, but nothing as changed and why would only the corys be affected?

Thanks in anticipation!