hi recently i noticed some of my african cichlids flicking and rubbing against the tank decor occasionally. tank is a 3ft and as for my water parameters, both ammonia is at 1.0, whereas nitrite is 0, as for nitrate is 12.5. is this ok? i have also done a 30% water change as i suspect it could be external parasites affecting them. are there any recommendation of medications for such cases?? also must i add in a heater to increase the temp?? pls help as i do not want to lose any fishes as they have been with me for close to 2 years.