I am sorry to hear. But I am going to be honest with you and I dont disrespect anybodies opinions here.
But I am getting tired of seeing people say that their waters were good. They usually always are. We see this all the time,,,,,,,water was good,,,ph is good,,etc.etc.etc.
BUT,,,I have had many years of exp. with these fish and will tell you I have also gone through ALOT of them trying to figure out WHY I was losing them.
These fish a way to sensitive to
WATER CHANGES,,,regardless when you do them,,,,
I tell you,,,,try NOT doing water changes for as long as you can stand it. These fish are AFRICANS,,,,,they will swim in toilets and survive.
People tend to believe that they are "supposed" to do water changes to keep fish alive,,,true in some cases,,,but NOT most.
Experiment with NOT doing a water change with your fish,,,if you do water changes weekly,,,skip a week,, if you do every 2 weeks,,,skip 2.
When I learned about these fish's sensitivities towards WC,,,,I/they were lucky to get them ONCE a month.

Before you debate me,,,,,,try it.
kEEP US POSTED.
APII.