Sorry about that, not sure what went wrong
Tank =180L
PH=7.8
Ammonia=0
Nitrite=0
Nitrate=40? (40 out of tap, lots of plants)
Temp=25C
Volume and Frequency of water changes: weekly 25%
Rummynose & silvertip tetras,T.Hengli, otos, Amanos
Symptoms sum it up really.
Dark colouring,listless, sitting on the bottom not eating.No obvious sign of illness
No change to routine or new additions.
Did large water change yesterday after symptons appeared.