Transcript of Heart Disease and the Excretory System. Heart Disease and the excretory Heart disease slows the oxygen flowing throughout the body. So oxygen moves slower to the excretory system.
The most likely causes of a shift in pH are: 1  Something in the water source buffering the water. 2  Something in the tank buffering the water. 3  or Something you are adding to the tank.
Here's How: 1  Test the pH, and chlorine levels before adding fish to a new tank. Chlorine must be zero, and pH close to that of the pet shop. 2  Turn the light off in the aquarium to reduce stress. 3  Lift the lid and place the sealed bag containing the fish in the water so it floats.