Pond vac and brush suggestions

[BarbAZCA]

I have string algae that collects on the bottom of my pond - 3' down. I'm looking for suggestions on long handled brushes and pond vacs to help in removing the algae and other muck on the bottom. I have 11 three year old goldfish and many small babies that I wouldn't want to suck up. After researching and reading reviews, it has become a nightmare - so many negative reviews. I'm hoping to get positive experiences from users on the forum. Thanks in advance.