The glue from the tape will just get wet and slide off, so its useless and im not sure if its safe for fish.
Buryingunder the gravel worked for me, i suggest you just go to your lfs and buy some aquarium slicon and use that, and you will have alot left over and i bet you will find a good use for it. I used mine just to glue rocks togeather, and now im making DIY power head filters, whats next?.