Is watercress considered an invasive in Florida? If not, it might be something to try. It uses nutrients as well as hyacinth in my pond. I have had watercress in my pond for years, but just this year really got serious with it because I couldn't get good hyacinths.

This year a made a tubing hoop and lashed some bird netting to it. Toss some watercress on top and you have a floating watercress forest in the middle of your pond. The roots hang down and suck up nutrients.

i had that crud earlier this year. i did add some more plants (hyacinths)and potash and it cleared up in days. now i have some other kind that is growing up from the sides and bottoms in individual strings, i guess string algae. water is clear though and this stuff is not near as nasty looking as that floating stuff.

Sounds like filamentous algae, often referred to as pond scum or moss. Growth begins at the bottom and rises to the surface as a bubble filled mass. You mentioned you tried bacteria and it did not work. Bacteria is designed to reduce muck and the nutrients that bring on algae growth, but unless used religiously does not prevent algae. You can mechanically remove the blooms, add aeration which lets decomposing material naturally release the toxic anerobic gasses, followed by natural bacteria.

Larryl, I didn't know about watercress, but when I looked it up, it also is on the invasive list here. Very frustrating. I want to do the right thing, but I don't want to look at that ugly stuff.

Jeffken, I think we will have the pond professionally vaccuumed. We clear it of leaves as much as we can, but there is still fine stuff- muck at the bottom. Maybe after that the bacteria will have a better chance? The skimmer removes the blooms, and we clean the skimmer pad daily now. There is a small waterfall, but sometimes I get the hose and provide more aeration too.

Any other submersible plants that don't multiply rampantly? Any other ideas? Thanks!

Anna

Yep it's algae but it's alled cyanobacteria because it's a strange combination of plant and animal. And yep it really is a bacteria. It's also called blue-green algae. Sometimes it's green and sometimes it's reddish brown in color. It can get really thick and bubbles form in it. I've seen it several inches thick with so many bubbles forming and popping that it sounds like a giant bowl of Rice Crispies.
Controlling the phosphorus level in your pond will keep it down, calcium bentonite sprinkled on top of it will slowly kill it and a lot of floating plants will also keep it down.

Floating plants like water hyacinth, pennywort, watercress, bogbeans, yellow monkey flower. Anything that has a massive root system that floats. Lily pads don't count as floating plants.

As for beneficial bacteria? Well it seems that somewhere down the line somebody started a rumor that beneficial bacteria kills algae and does all kinds of other strange things.

The beneficial bacteria does two things and of course there are two separate types.
The first type eats ammonia (fish poop) and excretes NITRITES. The second type eats nitrites and excretes NITRATES. This cycle converts poop into plant food.

That is the ONLY thing that the beneficial bacteria do. Nothing else.