Abstract: A casing system for a tank such as a storage tank for restaurant cooking grease. The system includes a slotted bracket secured on each of four corners of a tank top, to each of the brackets corner supports are attached for holding exterior panels used to give the tank a finished appearance. The corner supports have bent portions, including terminal parts which are bent further into substantially an S-shape. A pocket or channel is created in the terminal parts of the supports into which the edges of plastic or fiberglass panels are received and held securely. The supports can be moved or adjusted slightly in the tank brackets to allow for fitting panels which have been cut slightly off-size and thereby save waste. The assembled panels and supports give a smooth, finished appearance to the tank.