Pond Boss Forums GENERAL QUESTIONS Muddy water Floating clumps of suspended clay

We have what appears to be floating clumps of suspended clay soil, sometimes topped with grass clippings or occasionally sprigs of green grass growing on top of the clumps, that collect on top of our 2 acre lake every summer. They begin on the shallower shoreline areas, but collect on first one side of the lake and then the other, depending on where the wind pushes them. On completely still days, the little clumps may be scattered all across the lake. Except for shoreline areas, the lake is very deep (60 ft. in the center) to hold irrigation water.

Is there any way to get the suspended clay to drop back to the bottom? Any help would be appreciated, as the clumps really destroy the aesthetic appeal of the lake!

Winona, I've never heard of floating clay. It is usually heavier than water. Can you post some pictures of them

I tried valiantly for an hour to get a photo uploaded, but I haven't been successful. I'm a new member, and perhaps I missed a step somewhere, but more than likely it's my miserable internet connection in this rural stretch. I will try again, and label it as floating clay.

I talked with the people at ProSkim about their neat unit for skimming surface weeds off a lake, thinking it would be a great solution for me. But they said that what I described sounded like electrostatically charged clay, topped with grass clippings and an occasional topping of green spikes that rooted into the floating clumps soil. They said floating clay was often seen in the southeastern portion of the country.

The only submerged weed we see in this lake is slender spikerush along some shorelines, and I'm told that slender spikerush is just about impossible to kill. I can see that same type of soil-like topping on the spikerush under the water--it looks like the same stuff that is floating on top of the lake. When I do get a photo up, you will think it looks like algae, which it looks like from a distance. I tried Cutrine plus, copper sulphate, etc. early in the year trying to keep this stuff from proliferating, but no go. I thought maybe it was brown algae.

We do spray with Accord along shorelines for aquatic primrose, but Accord and algae control are the only chemicals I have put in this lake. Our 7 acre lake on the top side of the dam looks great--none of this stuff. This lake is newer, built 5 years ago.

Thanks for the response DD2 and I'll try to upload a photo again.

I posted more photos, so if anyone knows what this is and how to get rid of it, let me know. Thanks.

Looks like your photos were addresses by Ewest and Esshup. My opinion, too, is that it's just filamentous algae (FA). You have excess nutrients and this crap is a typical byproduct. Figure out your source of the nutrients and you can work on minimizing them. In the meantime, if you don't mind the chemical approach, try some Cutrine Plus, a copper based product. Wiped out all of my FA after a few treatments this summer.

Thanks everybody, Ewest, Esshup and Todd3138, for the replies. I'll take your word for it and get to work on it.

Winona

winona:

If you want to try a small sample test, scoop some out and put it in a wider than tall container (using water from the pond as well). Plastic cement mixing tub, etc. Hit it with your preferred chemical of choice and see if it kills it. If not, you aren't out a whole bunch of chemicals.

If it does, but it doesn't in your pond, then you know that the chemical concentration isn't enough in your pond.

If this really is algae, wouldn't I have to spray it with a liquid in order to have a chance to penetrate the mat? I prefer granules, but I tried that last year and it seemed like the granules just sat on top. Maybe I got impatient, but we finally pulled what we could out of the lake with rakes. The lake looked a lot better, but it made a mess of the shorelines. With so much of this stuff, what's the preferred application method to reach it all and have a chance to minimize it?

Or would around 200 lbs of hydrated lime around the edges be a possible way to treat it, given it's a 2 acre lake?

Winona - For various reasons, including your ponds presumed geography and a hunch, I suspect your annual pond-visitor is LYNGBYA.
I certainly can't verify this hunch simply by viewing your photos Photo 1 Photo 2 . However, one notable characteristic might support the suspected ID. Lyngbya usually has an odor similar to freshly dug soil. I don't know how else to describe it, but you'll probably know what I mean if you take a whiff and it is truly one of the lyngbya species of algae.
In my limited encounters with this very tough and tenacious pest, it often forms on the bottom of ponds and lakes - even in relatively deep, but clear water. At some point, it becomes bouyant; floating to the surface in broken mats and bringing with it plant fragments (including pine needles) that have previously sunk to the bottom, and also providing a floating substrate upon which seeds are able to germinate and grow.
Check it out from this perspective and see what you're able to determine.

Great advice here, winona. Definitely give it the smell test. I also agree with esshup that trying to chemically kill it in a controlled environment is a good idea to see if you have something that will do the job.

The sludge may well be your average surface coating algae from the bottom of the pond. As it photosynthesises, it forms bubbles of oxygen which can make it become buoyant early in the day, surface coating algae and bits of what it is attached to, float to the surface...

A hefty rainstorm, or harsh spray of water might be effective to agitate the sludge so the bubbles of oxygen that are making the mass buoyant are dislodged and the material settles back down to the bottom.

Cutting down nutrient inputs into the lake, stepping up plant competition for those nutrients (waterlilies, iris etc.) can eliminate such algae blooms by starving the surface coating algae. Repeatedly extracting the sludge will also reduce the problem of too much fertility in a pond lacking a balanced ecology

Regards, andy

I hope not Kelly as that stuff is very hard to deal with.

Thanks everybody. You've given me a lot of information. I'll experiment on a small scale and see what seems to work. Here's hoping it turns out to be one of the easier things to deal with, rather than one of the worst....Really appreciate your input.

I have some stuff that looks like this as well and thought it was FA but now I am concerned. It looks like Grass Carp may eat it if nothing else in there for them to eat, I wonder in Tilapia will eat it as well does anyone know?

Since it is getting so late in the year what would be my best step to work on this now?

Thanks

Giant Lyngbya is a type of FA. One that is very hard to deal with.

So what are my options to deal with this problem?

Add Grass Carp and Tilapia?

Nuke It?

Drain and start over?

I would try tilapia. Blue tilapia at the correct stocking density have worked really well so far in the ponds where I have used them for this problem. IMO stocking density is the key to success if you go the tilapia route. Keep in mind that unless you change the pond conditions that are favoring the algae mat growth the algae will persist. Favorable conditions: clear water, often presence of blue dye, all other pond bottom plants have been eliminated, no bottom activity, usually black underlying sediments.