Ultra sonic algae killer

[Thomas Barr <tcbiii at earthlink_net>]

I've known about a number of ultrasonic devices that kill algae very
effectively by imploding their vacuoles causing them to die for some time.

 The sonic pressure is enough to kill many algae and even some larger
filamentous species. Apparently, in talking with a commercial Dutch company,
They had no effects on fish, invert's and higher vascular plants.
They use these for larger ponds etc but the acoustics of our tanks is such
that it would greatly amplify the sound compared to a lake etc.

They make ultrasonic foggers relatively cheap. Perhaps modification of such
a device by using a controller to change the frequency to the right range to
be lethal for algae would be all that's needed.

It seems like a benign, easy add, device that one would simply toss a small
"speaker" that floats on the surface(or wherever) till the algae is gone and
that's it.  

Ultrasonic foggers are cheap and converting one to this should not be that
difficult it seems to me. Maybe 50-75$.
The larger units for ponds etc run about 600$ and up. I believe the
frequency is changed back and forth to yield the desired effect.

Regards, 
Tom Barr