How to Remove Algae From an Air Conditioner

Locate the outside drain line near the air-conditioner unit.

Remove the paper filter from a wet/dry vacuum cleaner, as the algae may ruin it. The filter is typically located in the top of the device, just below the hose connection. Read the manual for your vacuum model if you are unsure how to open the vacuum housing.

Place the vacuum cleaner directly beside the drain line. Plug the vacuum cleaner into an electrical outlet, using a heavy-duty extension cord if necessary.

Hold the vacuum cleaner hose against the opening of the drain line. Wrap a towel tightly around the connecting point to create a seal.

Turn on the vacuum. Let it run for five seconds to suck out the algae.

Locate the drain pipe access point on the inside of the house. This should be located directly on the other side of the wall from the outdoor drain pipe.

Pour 1 cup of bleach into the pipe to kill any remaining algae. Repeat this process every spring to prevent algae buildup.