What did you clean with? Did you remember the dechlorinator?
I am sorry to hear about your losses.
Don't clean or change your filter pad, gently rinse in treated tap water only if needed. Also should not clean filter and tank and or gravel/sand and water all at once either.
You need to keep the water good for the Cories.
What are your readings for your water parameters now after the water change?
I am sorry to hear about your losses.
Don't clean or change your filter pad, gently rinse in treated tap water only if needed. Also should not clean filter and tank and or gravel/sand and water all at once either.
You need to keep the water good for the Cories.
What are your readings for your water parameters now after the water change?