Cholla Wood Made from an all-natural, dried husk of the Cholla cactus, its porous structure and soft texture make it both a unique aquarium decoration and a functional feature. You can use it as a base to attach Anubias, Java Fern and aquatic mosses, or as a site for small fish and shrimp to find food and shelter. It’s also great as natural decor and a climbing surface in your hermit crab habitat. Whatever you choose, it comes with two hand-selected pieces that measure approximately 3 inches long and .50 to 1.5 inches in diameter Great for shrimp tanks! Unlike most types of wood that are used in the aquarium, cholla is soft and breaks down over time. During this process all kinds of beneficial processes happen. As with Indian almond leaves and alder cones, tannins are released into the water. This can stain the water a slight yellow color, which some consider unsightly but actually helps imitate the natural habitat of many shrimp species. Most importantly, though, tannins have antibacterial and antifungal properties which help protect your shrimp against disease. As cholla wood breaks down a layer of biofilm forms on it. This makes it the perfect place for shrimp to forage; a piece of cholla wood will likely have a few shrimp on it at any given time. Cholla wood will take a day or two of soaking before it will sink but once water logged they will stay where you place them.