Biotic or abiotic factor

6. you notice algae growing on the sides of the tank and the rocks. is this an example of a biotic or abiotic factor? how do you know?

7. you decide to buy a snail to eat the algae on the sides of the tank and rocks. is this an example of a biotic or abiotic factor? how do you know?

8. while you’re at school the lightbulb for the fish tank burns out. is this an example of a biotic or abiotic factor? how do you know?

6. Algae are biotic factors. They are living organisms which have the capability to produce food through photosynthesis. It acts as a producer. Also they appear on the wall of tank  through reproduction , which is characteristics of living being.

7. Snail is also a biotic factor like algae. They are classified as consumers. They feed on algae to survive with in the tank. They move while feeding on algae and movement is an important trait of living being.  

8. Light Bulb is an abiotic factor. Though it is an essential requirement for fish to survive but since it is not a living being , it is considered as abiotic. While fish  on the other hand is a biotic factor as it possess life in it.  

it's unlikely a majority of a large population would agree on issues

hope this : )