Nitrate
Reducing nitrate with carbon dosing in a fish tank.
When keeping fish, one of the goals to reduce algae is to keep nitrates to a minimum. One way of doing this is to dose a carbon source which nitrifying bacteria within an aquarium consume together with nitrates. The carbon source must be dosed very precisely.
Make
Write a program that outputs how much carbon to dose from the nitrate. Greater than 10 is 3ml, greater than 2.5 is 2ml, greater than 1 is ml, or 0.5ml if the nitrate is equal to or less than 1.
Use this boilerplate code as a starting point:
Success Criteria
Remember to add a comment before a subprogram or selection statement to explain its purpose.
Complete the subprogram called `calculate_dose` so that it:
- Calculates the carbon dose as 3ml if nitrate is greater than 10.
- Calculates the carbon dose as 2ml if nitrate is greater than 2.5.
- Calculates the carbon dose as 1ml if nitrate is greater than 1.
- Calculates the carbon dose as 0.5ml if nitrate is 1 or lower.
- Returns the carbon dose.
Complete the `main program` so that:
- The user can input the nitrate level as a decimal number.
- The correct carbon dose is output.
Typical inputs and outputs from the program would be:
Enter the nitrate level from the test: 25
For 25.0 nitrate dose 3 ml of carbon.
Enter the nitrate level from the test: 6
For 6.0 nitrate dose 2 ml of carbon.
Enter the nitrate level from the test: 1.25
For 1.25 nitrate dose 1 ml of carbon.
Knowledge Organiser
Use these resources as a reference to help you meet the success criteria.
Programming guide:
Flowcharts:
Parsons:
Evaluate
Run the unit tests below to check that your program has met the success criteria.
Enter the nitrate level from the test: 50
For 50.0 nitrate dose 3 ml of carbon.
Enter the nitrate level from the test: 7.25
For 7.25 nitrate dose 2 ml of carbon.
Enter the nitrate level from the test: 2
For 2.0 nitrate dose 1 ml of carbon.
Enter the nitrate level from the test: 0.5
For 0.5 nitrate dose 0.5 ml of carbon.
Check that you have:
- Used comments within the code to describe the purpose of subprograms and conditions.
- Used meaningful identifier names. That means the names of subprograms and variables indicate what they are for.
