Last week a friend gave me his 3 ft fish tank as he no longer wants it. I got an old hood from a friend (the normal black one's) but it looked quite faded as it's a very old hood. I have polished it using sunflower oil and now it shines more brightly than a new hood. I wanted to ask if sunflower oil would be harmful for fish / plants? I only put oil on the top of the hood and will polish the excess oil off in a few days and then wash it so it should be fine (I hope).