Dying Cory :(

[ihassomefishes]

hey guys...

i woke up this morning to find one of my corys in a bad state-he's laying on his side breathing heavily, every once in a while he flies around the tank really quickly and erratically, and his right fin is clamped.

i had my tank cycled, but i added a couple of platys and it went haywire-i had a .25 ammonia reading a couple of days ago-did a partial water change and it returned to zero.

now:
nitrites-0
nitrates-5ppm
ammonia-.25ppm (ugh, i did a partial water change and now it's reading 0)
pH-7.6

so, i guess it's ammonia poisoning...is it too late to save him? how often should i be changing my water now that things are wonky?

thank you

 

[ihassomefishes]

he died, i think--i can't find him anywhere in the tank.

could the others have eaten him? i'm worried about an ammonia spike if i can't find him, but i've checked everywhere.

advice?

 

[emmettbaby]

What else is in the tank? Just platys? How many? Did you change anything recently, other than adding fish? How many gallons is your tank?

 

[the biffster]

how long did it take to cycle
the tank