One of the best things about TikTok is its never-ending supply of helpful life hacks. Most recently, in a viral video by TikTok user KD (@sheiskd_), a whole bunch of people got schooled in physics as it relates to liquid laundry detergent — yes, laundry detergent.
The video starts by showing one of those big liquid laundry detergent containers with a spigot at the bottom. KD opens the spigot and only a trickle of detergent comes out. Frustrating, right? No one likes waiting around for the detergent cup to fill up.
Video of the Day
Video of the Day
Then, KD twists the valve at the top before opening the spigot again, and it's a full-on detergent waterfall.
So what gives?
When you have a closed container filled with liquid, and you want to get that liquid out, you need two holes in the container to create a smooth pour. The liquid will only pour out if air comes in to replace it inside the container.
The issue is a lack of air in the container, which creates a vacuum when the liquid flows out. When you have two holes — as represented by opening both the upper valve and the lower spigot on the laundry detergent container — the air can flow through one as the liquid flows out the other, equalizing the pressure inside the container and breaking the vacuum.
This is why tumblers and other closed drink containers always have a tiny hole on top — to let air in.
Many commenters point out that opening the valve is written right in the directions on the detergent container. While that may be true, we're pretty sure many people skip the directions on this seemingly simple task. And given that this video has more than 16.4 million views, we're thinking quite a few people found this tip helpful.
There's just one thing to note: As other commenters mentioned, you don't need to use that much detergent per load of laundry. Generally speaking, it's best to use about one to two tablespoons of liquid detergent per load.