Exploring the Science Behind Air Bubbles in Pools and Lakes

In summary, when you kick around in a pool or lake, air bubbles seem to stream from your feet. But what causes this? It's either air being pulled down from the surface or oxygen from the water molecules.
  • #1
schaefera
208
0
When you kick around in a pool or lake, air bubbles seem to stream from your feet... But what causes this?

Is it air being pulled down from the surface, or oxygen from the water molecules, or something else entirely?
 
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  • #2
schaefera said:
Is it air being pulled down from the surface
Yes.

There's one other way bubbles can occur in water - but I doubt even the best swimmer can kick fast enough to cause cavitation.
 
  • #3
Apparently the right term for what is happening is 'ventilation'. It happens with boat propellers operating too near the surface.
 
  • #4
sophiecentaur said:
Apparently the right term for what is happening is 'ventilation'. It happens with boat propellers operating too near the surface.

Yep. Learned that one recently while repairing my motor. The big wing on outboards just above the propellor is called an anti-ventilation plate.
 
  • #5
PF certainly does widen our horizons - in the rush to be the best informed poster of the day. :wink:
 
  • #6
Well that wing on outboard engines used to be called a 'cavitation plate'. I wonder if air pulled from the surface [ventilation] is now distinguished from cavitation which is a pressure induced phenomena in liquids??

Anyone have a reference that uses 'ventilation' for such bubble induced wear and tear? Wikipedia, for example, discusses what I have always known as 'cavitation' issues. I have never seen 'ventilation' terminology in marine applications. Maybe they modified terms??

I can verify that certain prop wear on larger boats, bubble induced noise on props,and even oscillation induced metal wear in water cooled cylinder liners in some diesel engnies [ like the Detroit Diesel 53 series] is called 'cavitation'. It is common practice in some older boats to double up on hull thickness right over props and sometimes inlcude sound deadening material there to combat such unwanted noise. In wet liner diesel engines, the manufacturer [DD] specificies certain additives in engine coolants and or antifreeze..nitrites, if I recall.
 
  • #7
DaveC426913 said:
There's one other way bubbles can occur in water - but I doubt even the best swimmer can kick fast enough to cause cavitation.
There is another way. But I doubt the swimmer is hot enough to cause boiling :biggrin:.

@Naty1 <-> sophiecentaur and DaveC426913: I think you are talking about different effects.
 
  • #8
I was waiting for that comment. I managed to restrain myself.
 

1. What causes air bubbles to form in pools and lakes?

Air bubbles in pools and lakes are typically caused by a process called gas exchange. This occurs when gases, such as oxygen and carbon dioxide, dissolve in water and then are released as bubbles when the water is disturbed or agitated. This can happen naturally due to wind or waves, or can be caused by human activities like swimming or using pool equipment.

2. Are air bubbles harmful to humans?

No, air bubbles in pools and lakes are not harmful to humans. In fact, they can be a sign that the water is well-oxygenated, which is important for aquatic life. However, if you are experiencing excessive amounts of air bubbles in a pool, it could be a sign of a malfunctioning pool pump or filter, which should be addressed for proper water circulation and filtration.

3. Can air bubbles impact the water quality in a pool or lake?

In most cases, air bubbles will not significantly impact the water quality of a pool or lake. However, if there is an excessive amount of air bubbles present, it could indicate a problem with the water circulation and filtration system, which can lead to decreased water quality. It is important to regularly monitor and maintain these systems to ensure proper water quality.

4. How can air bubbles be prevented in pools and lakes?

Air bubbles in pools and lakes are a natural occurrence, but there are some steps that can be taken to reduce their presence. Ensuring proper water circulation and filtration is important, as well as avoiding activities that can cause excessive disturbance to the water, such as diving or using pool toys. Regular maintenance of pool equipment is also crucial in preventing air bubbles.

5. Are air bubbles a sign of a leak in a pool or lake?

Not necessarily. While air bubbles can indicate a problem with the pool's pump or filter, they are not always a sign of a leak. However, if you notice a sudden increase in air bubbles along with a decrease in water level, it could be a sign of a leak and should be investigated further.

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