Does the Permeability of Water Prevent Surface Disturbance in Aquariums?

[Kaustubh sri]

When we look in the aquerium , the fish moves from here to there but there is no disturbance at the surface of water . Why is it so?

My attempt
Actually I think that this problem is due to permiability of water. Am I right or wrong?

 

[CWatters]

permeability of water? Do you mean the compressibility of water? It's not that.

If the fish is deep enough the disturbance at the surface has a small large radius. Water also flows quickly so it's self levelling.

 

[Kaustubh sri]

What do u mean by small large radius

 

[SteamKing]

What do you mean by 'the permeability of the water'?

 

[Kaustubh sri]

I mean to say water flux

 

[CWatters]

What do u mean by small large radius

Sorry I made a typo. I meant

If the fish is deep enough the disturbance at the surface has a large radius.

 

[Kaustubh sri]

Sorry I made a typo. I meant

If the fish is deep enough the disturbance at the surface has a large radius.

But if the fish is at the near the surface than

 

[CWatters]

http://www.evols.org/mediawiki/images/thumb/e/ed/BL-06-1-streamlined.png/250px-BL-06-1-streamlined.png

 

[olivermsun]

There is indeed a disturbance at the surface of the water; it is usually negligibly small because the density difference between air and water is so big.

 

[HallsofIvy]

Because of the viscosity of water, any time water moves, there is a loss of energy. If the fish is deep enough under the water, the energy will have dissipated by the time the disturbance reaches the surface.

 

[Kaustubh sri]

Thanx Cwatters and olivermsun I got it