A hydrolytic bottom is designed for the customer that is prone to dropping parts and possibly causing damage to the bottom of the tank liner. The second bottom is spot welded in place but not sealed. By allowing the fluid to stand between the liner bottom and the second bottom, a shock absorber effect is created. When a falling part hits the first bottom, it is slowed down by the shock absorbing fluid. In turn, the part does less damage. Typically, the hydrolytic bottom is made of 3/16” thick PVC, but any thickness or grade is beneficial in preventing damage to the actual liner bottom. So, if mechanical failure caused by dropped products, tools, etc. is a likely occurrence we would recommend using a Hydrolytic bottom.