A stagnant or standing water source can be a breeding ground for mosquitoes, but luckily there are products designed specifically for safely eliminating mosquitoes from these locations.
Be careful not to add any harsh chemicals and pesticides to the water, because not only will they kill the mosquitoes, but there is a good chance that it will have a harmful and deadly effect on fish and other animals that you do not wish to harm.
I recommend that you use mosquito dunks, as they are specifically designed to target mosquitoes while having a minimal effect on other wildlife and living organisms who depend on the water source for survival. All you have to do is drop the mosquito dunks in the standing water source, and let it go to work.
