I tried to grow it but I had too much water movement. It likes still water. Maybe set up a pump to move the water on the surface?

thank you so much for the suggestion, I'll have to see what I can work out.
That might also explain why it grows less when there's a lot of rain--that tank gets the runoff from my garage roof from a height of 8 feet, churning the water a lot.

Well, I used a garden hose to push a lot of the azolla toward the skimmer, and scooped a lot of it out.

I've done this before, and it all came right back, but this time, the weed is much slower to recover. Maybe if I do this once a week or so, it will keep it manageable.

thanks for the idea!

On ponds where azolla has smothered the whole area, I found by raking the bulk of it to one side and leaving it piled up on itself sets off some allellopathic condition which kills the whole lot off

I haven't done anything about the azolla for over a month, but it's nearly gone!
Must be a seasonal thing?
Or the goldfish developed a taste for it?
Or the water hyacinth and lilies are sucking down the nutrients?

if you ever want to get rid of it again, please consider sending to me and I WILL PAY postage as I lost all my plants and fishTY

nice idea, but the USDA has stringent regulations about what can be shipped out of Hawaii. Since this is clearly an invasive plant, I don't think they'd allow it.