Results of the water tests

TANK A: 
pH: 7,2                7,2              6,8
NO3: 250            250             250
NO2: 0                1                 0
GH: 6                  6                 6
KH: 10-16          16               16

TANK B:
pH: 6,4               6,4               6,8
NO3: 100           250              100
NO2: 0               1                  1
GH: 0                 6                  6
KH: 10-16         16                16

TANK C:
pH: 6                 7,2               7,2
NO3: 250          50                50
NO2: 0              1                  1
GH: 3                3                  3
KH: 6                3                  3

MY RESULTS:
pH: 6
NO3: 0
NO2: 0
GH: 4
KH: 6

From these results, it shows my water is more acidic because my ph levels is lower than it should be. My water hardness is fairly low so my water is soft and my carbonate hardness is low.