virginian11Sep 5Selling Vivagrow DN 24/7 light (30"-36"). Also possibly a Finnex Planted+ CRV 24/7 (48"). Both in excellent condition from 2020. 31
That looks like Duckweed to me.
Not Duckweed, which has smoother surface.
It looks like salvinia. If it is the top looks harry.
Most likely Salvinia. Thanks Frank.