Today I decided to clean the water-pump filter of my swamp cooler, and there were a couple of larvae swimming in the water reservoir and some mosquitoes flying over it. I am looking for a way to kill the larvae and prevent the mosquitoes from breeding here in the future.
I can't drain the coolers everyday. It is a tedious chore if done manually. And it wastes a lot of water (around 70 liters per unit). Also I suspect that some puddles will remain in the cooler even after draining.
I can't use bleach or insecticides. The water comes into direct contact with air that people will breathe. I tried bleach a couple of years ago and it gave off a horrid smell.
So what other effective steps can I take to solve this problem? Doing some online research, someone suggested that I should add dish-soap to the water. Will that even work?