I have a stand that is slightly too small for my aquarium, and the guy at my lfs said that putting a plank across it should be fine since it only goes over the edge by an inch on the left and right sides. The problem is, the corners of the stand are slightly raised, so the bottom of the plank has no support directly under it, just on the corners. The wood is bowing under the weight of the aquarium and if I line myself up with the bottom of the aquarium I can see a tiny sliver of light through it. The aquarium is rimless and has a pad under it meant to distribute force. Will this be a problem in the future or is it safe as it is?