Mustafa - you will need to read up on plant nutrients. Besides CO2, plants need macro and micro nutrients. It sounds/looks like your macros (NPK) have run out, which will stop plant growth and eventually kill them. No plant growth also results in algae, and while you can add all sort of algae killers it doesn't resolve the situation. Forget about the algae and focus on your plants. Healthy growing plants are the best algae killer.