While doing a water change on my 5 gallon I had an idea. I have 2 ten gallon tanks behind my 5 gallon. Why not put the 5 gallon bucket on top of the 10 gallons rims and have it fill up the tank while I am emptying out the tank. I put the bucket on where the 2 edges meet on both tanks so it would have a better foundation. Is it possible that this will eventually crack the glass? It is 50 pounds of water so I am a bit concerned if I should continue doing this.