Sometimes spills and accidents occur when working on your tank. Occasionally, water will leak from an overflowing protein skimmer, or maybe you left the RO unit on and it’s filled your sump with multiple gallons of water. Either way, your stand is taking on water, which it is obviously not designed to hold. If the wood is unprotected, it could absorb a great deal of water. This of course is bad news, especially for stands built out of MDF/particle board, as the wood will great swell in the areas it got wet. Many hobbyists plan for water related incidents by placing a waterproof tray under their sumps, or at least some sort of plastic material to keep water off the wood and from ruining the carpet. Others may line the inside of the stand with some type of sealing chemical or coats of epoxy or polyurethane. The options are limitless, with the only real goal being to prevent water from ruining your stand or the floors underneath the aquarium.