Sluggish fish helpp

Bublewrap11

One of my african freshwater fish, is acting veyr sluggish, and almost sick like. I looked for the different symptoms of sicknesses, but the fish doesnt seem to have the salt like stuff on her scales, nor frayed fins, and she isn't swimming upside down a whole lot. Every now and then she will, but it's not that common. Is she sick and i can't find the treatment?? She acts very sluggish and tired, she hasn't been eating the food i'm giving them(there are two other fish) and she seems like she's a zombie almost. I'm really worried but I don't really know what to do. I just cleaned their tank today, i let it oxidize with the air pump for at least 20 minutes before i put them back in, and yes the water temperature was stable, so i know that can't be it. If anyone knows, I'd really appreciate it. If you need a picture of the fish email me and i'll send you one. My email: navylifenavywife11@gmail.com

Byron

I won't attempt to diagnose what may be wrong as that is not easy (at least for me). But to assist those who have more experience in this, a photo would help. And some data on the tank: tank size; fish in the tank (species and numbers); water parameters (GH, pH, temp); test results for ammonia, nitrite and nitrate; water change schedule (volume and frequency); any substances going into the tank; how long has the tank been running, and when was this fish acquired.

I'm assuming this is a rift lake species, and we have several members with experience in this area, so with the above info someone will likely be able to offer assistance.

Byron.