Bodkins, sucahyo
About the Blowing water.
It follows PP that the "wind" would stop as the spark starts.
One stress gives way to another stress that takes it's place.
That goes along with different kinds of sparks, static and ions, different stresses..?
There are so many things that can be happening all at the same time.

I was wrong. I said you can smell ions.. No, you can smell Ozone.
I did not find cold or cool air related to ion lifters.
I've read some where that there is debate about if a lifter really is
moving air via an ion flow or is it something else moving the air.
A stress could be moving the air with some ions tagging along.
Knowing what it is or what it is the nature of it, might allow using that
information to increase strength or channel it.
This shows a lifter and the wind blowing out a flame.
UFO Lifter

OZONE and NEGATIVE IONS: Frequently asked questions
An air ioniser (or negative ion generator) is a device that uses high voltage to
ionize (electrically charge) air molecules. I'm curious what is being ionized in
an ion engine for space Ion Propulsion? (never mind..)
See this one Ion propulsion .. tesla-powered ion motor.

These are not lifters.
ion thruster IV
YouTube - ion thruster IV
YouTube - ion thruster III

If it is not ions and not magnetic .. knowing more about the properties would
be a good thing.
Ruling out diamagnetic/magnetic effect via a paper clip or something on a string
to test for magnetic field around non-sparking wire?
sucahyo showed video of paper being attracted to wire, that could be static
charge.

Could you not use a candle just as well as water?
If I remember correctly, a flame is diamagnetic also.. that's does get any
answers magnetically .. A flame has it's own little world of stress fields.
How does shape or the geometry of the HV effect the moving of water.
If the HV is a catalyst creating the wind or is it the direct cause of the
wind? If a shape changes the strength of the wind that might give clues.

Folding or taping AL foil to shapes might be good to test shapes.
Triangle, Sphere, pyramid, tetrahedron, Octahedron

Other shapes to feed your mind, eye-ball these.
Hypercube - Wikipedia, the free encyclopedia
Simplex - Wikipedia, the free encyclopedia
Convex regular 4-polytope - Wikipedia, the free encyclopedia
Cross-polytope - Wikipedia, the free encyclopedia

Do not stare too long at this image, it will warp your brain