I'm trying to get vegetation reestablished in a 60 acre gravel pit. Grass carp killed everything, but they are starting to disappear. I'm having a hard time getting any plants growing, some hardy lilies and some spatterdock have grown but they don't flourish they just survive. The ph of my lake is 8.4 and the lake bottom is gravel, clay and some organic stuff. Are there plants better suited for a higher Ph, that would do well in a gravel/sand substrate. Thanks.

Have you tried water lettuce?
Its invasive, and known to take over.
But maybe you need an aggressive plant.

Water lettuce is a terrible idea don’t do that or your gonna have 60 acres of water lettuce. How deep is the lake

I don't know much about Water Lettuce other than is has similar characteristics as Water Hyacinth which means they both can be a nuisance in the right BOW (usually southern waters). I considered it for my pond, but went with WH instead.

60 acre gravel pit...I'd be beside myself!