hi last week thursday we did observation on all tanks in the practical, we were divided into groups and each groups came up with different results.
   GROUP 1
 TANK     PH  NO2  NO3  KH  GH
A               7.2   0        250    6     10-16
B                6.4   0         100   O     10-16
C                 6.0   O       250    3        6
BEST  B
WORST   A

GROUP 2
TANK       PH    NO2  NO3  KH   GH
A                7.2    1         250   6       16
B                  6.4   1        250    6        10
C                  7.2    1       250    3         3
BEST  C
WORST  A
 
GROUP  4
TANK         PH  NO2 NO3  KH     GH
A                  6.8   0       250    6       >16
B                   6.4   1      100     O         10
C                   72     0       25      6         10
 BEST   B
WORST  A

THE  SMALLER THE SYSTEM  DIFFICULT TO KEEP THE FISH. THE BIGGER THE SYSTEM THE EASIER TO KEEP THE FISH, IN THIS CASE TANK A  HAS BIG SYSTEM  THE TANK HAS THE FILTER AND THE WATER CHANGE IS NOT DONE REGULARY AND BUT STILL IS WORST TANK BECAUSE IT HAS LOT OF DIFFERENT FISHES AND THOSE FISHES ARE BIG , THEY CONSUME LOT OF FOOD AND THEY PRODUCE LOT OF WASTE .THE PH ARE HIGH WHICH MEANS PLANTS GET DAMAGED AND THE HARDNESS OF THE WATER  IS HIGH ,THE WATER IS HARD.TANK B THE WATER CHANGE HAS NOT BEEN DONE SINCE LAST YEAR AND THE PH FOR TANK B IS LOW AND ITS GOOD FOR THE PLANT , TANK B HAS LOT OF DIFFERENT PLANTS THAT ARE MAINTAINED WELL THE NITRATES ARE HIGH WHICH IS GOOD FOR THE PLANTS AND FISH , THE WATER QUALITY IS NOT BAD DUE TO THE FACT IT WAS DONE LAST YEAR . ALL THE TANKS HAS WEEDS , PLANTS ,ALGEA,TANK A HAS CYCLED SYSTEM ,STONE ,BIGGER TANK. TANK C SNAILS ,WATER IS WARM THAN TANK B, THERMOMETER.TANK   B HAS  ARTIFICAL LIGHT , THE TANK IS SMALL PLANTS BOTH FLOOTING ,SOIL.IN ALL TANKS THE PH ARE HIGH AND THE HIGHER THE PH THE MORE IT PUSHES UP THE NITRATES  ITS BAD , THE NITRATES ARE GOOD FOR THE PLANTS.