Hello; One method suggested for cat urine is to take up the carpet and replace the foam pad under it with new pad. Then clean the carpet with a machine. The tank water will have gone thru the carpet and pad and will be trapped under the foam pad which will take a very long time to dry, and will smell from the tank water as well as provide a place for mold to grow.
If you have hardwood flooring under the carpet, it will be damaged by the long time dampness. I had a tank leak into an area rug with no pad and thought I had dried it well enough. Turned out to have a black discoloration in the wood in the area of the leak.
In my current home I removed the carpet and pad in the area where my tanks sit and replaced it with vinyl tiles. I also sealed the edge of the tank area with plastic quarter round and silicone in hope of keeping a barrier from the rest of the carpet. I enlarged a hole in the floor where TV cable had run to allow the water a drain into the basement in case of a leak. In my experience tanks and carpet are not a good mix. If if there is not a major leak, there will be lots of spills around a tank.
Lets hope some one has a better solution.