Help... Young discus dying after water change

[MichelleRenee68]

I have 5 discus in a 55 gal. 2 are adult, 3 are juveniles. I always do 50% wc twice a week.Water parameters are fine, no spikes no changes, temp is 86. Well, today I did my usual 50% change, went out of the house for a few hours, come back and 1 juvi is dead and 1 is not looking good. I checked ph, nitrates, ammonia and a everything, all is within normal limits, temp is maintaining 86 degrees.

I am so worried now, I do not want to lose any more.. Any idea what has caused this? They were perfectly fine before the water change.

thanks

[AhKwaB]

what water source are you using and what preparations were done to it?

[supadave]

Sorry for your loss . Did the fish die with its mouth wide open ? The one that is looking bad......what is he doing ? Is he breathing heavy ? Is his movement sluggish ? Did you check the temp of the new water going into the tank ? Was the new water straight from the tap..or was it aged first ? What dechlorinator was used ?

[troy tucker]

Sorry about the loss.

[Ballinxalex]

sorry for your loss when u did your water change was it cold? i always use water from the tap but never had problems of losing discus +1 on what super dave said

[supadave]

Update ?