I used that type of material on top simply because all this wood was free, I had a full can of Thomson's water proofing liquid in my storage. I should of checked before filling up the thank with water. Im still debating on emptying out the aquarium and adding the Thomson's liquid to the wood. The only reason why I haven't done so is because I decided to do a water change on my other bowfront and transfer that water to this aquarium, I also used to filters that were on my other aquarium so that it could cycle faster. That's the reason why I haven't emptied out the water. Ill be posting pictures soon, btw, the bow front part of the aquarium is not sticking out, the stand my of given you that impression, but its actually just the lip of the top wood sticking out making it more like a bow front stand. The aquarium itself is completely on the stand.