Plastic Tanks have replaced tanks of most other materials especially fiberglass tanks over the last decade. Plastic tanks are especially good for storing water and most chemicals including chlorine, bleaches and acids. An advantage that plastic tanks have over storage tanks made from most other materials is much lighter weight. The weight saving means lower costs and greater ease of transport, handling and positioning. Tanks made from plastic are usually less likely to react to the liquid which is stored in them. The polyethylene material plastic tanks are used for holding drinking water and food products. Perhaps the most significant advantage that plastic storage tanks have is lower cost. In sizes up to about 16000 gallons, tanks made from polyethylene are significantly less expensive and deliver than are tanks made from most other materials. With the use of modern plastics, the lifespan of a properly used plastic storage tank can rival or exceed the life of most other tanks. Additionally, there is virtually no maintenance costs associated with tanks made of plastic. There are many types of plastic that can be used to make storage tanks. Polyethylene is by far the most common. Tanks made from a high quality polyethylene resin will be strong, durable and reliable over a long time. There are some chemicals that do not store well in polyethylene and for those substances other plastics like polypropylene or PVC may be more suitable. Tanks with a higher specific gravity rating will have thicker walls and will be designed for heavier duty use when compared to another tank made from the same material but with a lower specific gravity.