white shimmer

Ok guys, I'm getting rather disheartened by whats happening to my fish atm, here is a breakdown of whats happening.   Tank size: 250L pH: 6.8 ammonia: 0 nitrite: 0 nitrate: 5ppm kH: 7 gH: 12 tank temp: 26C Fish Symptoms (include full description including lesion, color, location, fish...