Lampeye Problems

[Willow 123]

I have a group of 20 lampeyes, lost one 2 days ago, thought it was a swim bladder problem, fish struggling to stop its self floating to the top, body a little contorted, not eating.
Today I found another one dead and I have 3 more exhibiting the same symptoms.
All tank parameters are fine, zero ammonia, zero nitrite, nitrate less than 10.
Anybody have any ideas?

 

[gwand]

What is the size of your tank? When was your last water change? What are your current ammonia, nitrite and nitrate levels? What other fish are in the tank? How many fish in total?

 

[Willow 123]

Just updated , all water parameters fine, last water change a week ago using api water conditioner

 

[GaryE]

How long have you had them?

There are a lot of different lampeyes (one of my favourite groups of fish). Are they Poropanchax normani, Norman's lampeye?

What are the tankmates?

 

[Willow 123]

Yep, Normans lampeye, had them about 3 weeks.
Only tankmates are a couple of bristlenoses (small) and 4 Amano shrimp

 

[Willow 123]

All are eating well, (brine shrimp, powdered flake, baby daphnia).