I like to use cholla hides in a shrimp tank for multiple reasons.
Like many botanicals, it produces tannins, which provide an anti-bacterial benefit. Thisnis beneficial to a shrimps immune system and may help buffer the ph a small amount.
They also are hallow with many small holes providing excellent areas for baby shrimp to hide and feel safe while snacking on the cholla which is slowly breaks down forming biofilm and holding holding algae on its pourous surface.
Lengths: 3-5", 6-8" or 9"+