Plants for shrimp shelter

Chunks of natural sea sponge work great too. They also provide a substrate for microbes that the shrimp eat, like a vegetable garden for shrimp. Just make sure that you get untreated sea sponges, and boil them to be safe.
 
Pearl Grass (Hemianthus micranthemoides), also known as baby tears (but not dwarf / HC), works great too. These grow pretty thick and very bright green for me in a wide range of lighting.
 
Riccia. Bind it to a rock or piece/branch of driftwood with a fine mesh like a hairnet or body scrubber. It will eventually grow out through the holes until a clump separates and floats away, but grab it, tie to another rock, rinse and repeat.*

*um, the "rinse and repeat" part is a joke based on instructions for using shampoo. You do not actually have to rinse the riccia before binding it to another base. :)
 
If you want something that grows fast and will fill up the tank...guppy grass as MG suggested or Hornwort.

Something a bit more controllable...java moss.
 
If you want something that grows fast and will fill up the tank...guppy grass as MG suggested or Hornwort.

Something a bit more controllable...java moss.

Marimo balls are nice, but grow slowly. I open them up and spread them out like a carpet. Pull them out once in awhile to rinse off mulm. Elodea works, too. Not much of a ground cover, though.
 
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