Ok problem solved:) I went to  michaels craft store bought a plastic mesh  for 2.50 and glue gun it to back after I empty tank and pulled out 15+ shrimp from the filter department. Hopefully that solves the problem I turn filter back on. 

Yep, cyanobacteria like Crabby said. Get rid of it as quickly as possible.

I feed my shrimplets powdered foods, that I pre-soak in a small cup of water (so the food sinks) and use a pipette/turkey baster and squirt the food into subwassertang or anywhere shrimplets tend to hide in.   2-3 times a week. 

That looks like blue-green algae, Cyanobacteria. It does quite quickly all across your aquarium and is extremely hard to get out. I recommend taking that piece of hornwort out (or at least trimming that part off), and maybe looking into how to get rid of it if it does start spreading more.

Try what Simon said. He’s spot on. You can try getting the shrimp out just with your hands probably, if they fit, not much we can do to help you there unfortunately.