Hi!!! In my algae control strategy I want to incorporate ultrasound tech.
I would need advise here and would like to hear the opinion of those of you wh have used this tech. Also, please tell me any recommneded brand you know works good.

Thanks in advanced

Several comments. Make sure it works on your predominant specie of algae. There are many thousands of algae species with a wide range of vulnerabilities to treatments. Some algae are very durable, some are very sensitive and easy to control and a wide range of species in-between. The sound method of control has a definite treatment range or distance that becomes less effective as the distance increases. I have not heard lots of success stories about its overall effectiveness for all types of algae. Buyer beware. I can see it working very good in a small backyard lily pond.

Sounds like the ultrasonic mosquito repellers. I remember a family member putting one right next to a resting mosquito which did not respond at all. As an entomologist, I told him he was using it wrong, so he handed it to me. I then squashed the mosquito with it.

http://www.sciencedirect.com/science/article/pii/S1350417717300950

I cannot imagine that method being good for the ecosystem in the pond, but interested to learn more.

Actually, ecological safety (specificity for algae) is its claimed advantage.

I would think that if algae is negatively impacted, there would also be other small organisms that would be impacted. What about the fish themselves? I don't know what their sensitivity to ultrasonic is, but at least with humans we may not be able to hear high-power ultrasonic, but it can cause headaches and a general feeling of poor health anyhow. The manufacturers claim otherwise, so perhaps my concerns are unfounded.

Reading up on it now, it sounds very interesting for controlling algae that is single-cell that uses air bubbles to gain access to surface light. It pops or disrupts the bubbles, causing them to remain on the bottom and die due to lack of light. So in other words, it is directed towards single-cell algae like BG algae and cyanobacteria, but probably does not impact more complex algae like chara and FA.

In all, very interesting technology to be able to target the nasty poisonous stuff in high-nutrient ponds.

My initial reaction was similar to your's, but after reading papers in the peer-reviewed literature, like you, I was surprised to see specificity for certain algae.