A really strange situation. Rescaped my tank on thursday, plants purchased from aquaessential (1-2 grow HC and 1-2 grow staurogyne repens. No fish or shrimps kept in this tank. Before adding the new plants i never had any problems with these critters. After rescaping on thursday everything looked fine. on friday i notice these critters so i done a water change today. Before that I added "panacur" to kill these animals, left it in there for a couple of hours before i done a water change. After doing a water change and letting it run for a bit i noticed more of these animals than before. Can anybody shed any light?
Here's a picture of what it currently looks like:

You can see all those critters floating around
Here's a picture of what it currently looks like:

You can see all those critters floating around