If it is a commercially finished piece of furniture, a little spill here & there should be no problem, as long as you wipe it up in a reasonable amount of time. If you are getting enough water on it to start causing damage, you are probably getting the floor soaked as well. If this is happening during regular maintenance, you need to slow down, or evaluate how you are doing maintenance. The only time I can see this happening would be a tank or filter malfunction. While rare, they have been known to occur.
Hoods are a different story. They are above the tank, constantly exposed to humidity & condensation. Multiple coats of spar varnish, which is designed for boats, is what is needed. There is also 2 part epoxy paint designed for coating the inside of water storage tanks. It's expensive, but designed for being in constant contact with water. Many people use it for coating the inside of homemade plywood tanks.
Hoods are a different story. They are above the tank, constantly exposed to humidity & condensation. Multiple coats of spar varnish, which is designed for boats, is what is needed. There is also 2 part epoxy paint designed for coating the inside of water storage tanks. It's expensive, but designed for being in constant contact with water. Many people use it for coating the inside of homemade plywood tanks.