It really depends on what you want to use the tank for and how much space you have for a tank. As a rule of thumb, choose the largest tank for the space available. If you are planning to put it by the side of the house or in a small backyard, a Nylex Slimline tank may be more suitable.
Measure the available width, length and height of the space and make sure the tank will not obstruct doorways, windows, eaves, external air conditioners, tree trunks or other obstacles.
Once you have calculated the available area, use the tank chart on the next page to select the right Nylex tank for your needs.