Pond Boss Forums POND CONSTRUCTION Soil questions Whats in the bottom of my pond?

I recently finished construction on my pond and its got about 6 ft of water. I went swimming in it yesterday to see how deep it was and theres about 1 ft to 2 ft of gunk above the bottom of the pond. Its not thick or anything but real mushy feeling. About 90% of my pond is clay. And also since i have so much clay i put a bunch of drywall in the pond to clear it up ( which worked great) but i wonder if all that gypsum is what i felt or if thats just how the clay bottom is? Does anyone have an idea of what that gunk is and is it habitable or harmful for fish?

Andy, it is likely just un-compacted clay washed into the bottom due to erosion as your pond filled. The small clay particles washed in from erosion will settle out in the deepest place of the pond. It is common, and will often compress itself in a year or two

Thanks Rainman. Will adding fish before it settles keep it stirred up? Or is it ok for fish?

I suspect that you are feeling the unconsolidated accumulation of flocculation of the gypsum and clay which has not fully settled or become more firm on the bottom. .

Maybe fiberglass fibers from the drywall?

I'd add fathead minnows if planned with only a couple feet of water....the fluffy stuff won't harm the minnows and they won't appreciably keep the fluff stirred. Like Bill said, probably some gypsum and/or the paper backing in the mix on the bottom as well.