Eshopps overflox box ques

Has anyone had the connetion to the overflox box leak? My sump kit came with a flex hose with a piece of pvc in the end of it then you just stick that into the connection coming out of the overflow box, it does fit very tight but was wondering if water could still possibley get threw or if the connection could come off all togather. That would cause small flood cause the sump is not directly underneth the overflox box. Is there anything i could put around the pvc before i connect it to the overflow box that is fish safe or would i even want to do that incase i ever want to get it lose again???