Tube settlers are commonly made from lightweight, durable materials that are resistant to corrosion, chemical degradation, and biological growth. The most usual material for manufacturing tube settlers is Polyvinyl Chloride (PVC). PVC is favored for several reasons:

1. 1. Durability: PVC is resistant to both physical and chemical damage, ensuring a long service life for the tube settlers under a variety of water treatment conditions.

2. 2. Corrosion Resistance: PVC does not corrode, which is particularly important in water treatment applications where various chemicals are used.

3. 3. Chemical Stability: PVC is resistant to many chemicals used in water and wastewater treatment processes, including coagulants and disinfectants.

4. 4. Lightweight: PVC's lightweight nature makes the tube settlers easy to install and handle, reducing installation costs and structural support requirements.

5. 5. Cost-Effectiveness: PVC is relatively inexpensive compared to other materials with similar chemical and physical properties, making it a cost-effective choice for large-scale water treatment applications.

6. 6. Ease of Fabrication: PVC can be easily cut and shaped into the required dimensions for tube settlers, allowing for custom configurations to fit specific treatment tank sizes and shapes.

Besides PVC, other materials like Polypropylene (PP) , FRP (fiber reinforced plastic) and High-Density Polyethylene (HDPE) can also be used, especially in applications requiring specific material properties such as higher temperature resistance or flexibility.