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.
There is no normal pH that applies to all fish. Because fish originate in ponds, rivers, streams, lakes, and oceans that have different pH levels, their needs are different. Saltwater fish prefer an alkaline pH of 8.0 or above.