How Much Water Does A 12ft. Round 30in Deep Pool Hold?

This cannot be answered, as in order to know how much, another dimension needs to be provided. If you are going to find out how much water your pool can hold then you will need to do the following equation;

• 12 feet multiplied by (missing figure - the length of the other side of the pool needs to be here) multiplied by 30 inches deep (this is 2.5 feet).
  
  
• The formula, put simply, is Length X Width X Height. The missing figure is required before you can be given the answer, but at least now you know that you can work this out for yourself. All you need to do is go out to the pool and find out what this missing measurement is. This will allow you to calculate how much water you need to fill your pool to a sufficient level (remember to save water; pools don't need to be full to the brim!). Fill the pool too much, and this may result in a problematic overflow when people get into the pool to swim.
  

If you are having issues sorting out the construction or filling of your pool, you should talk to either the contractors performing the work or the people that provided you with the pool. This will ensure that your pool is built and constructed correctly and any issues you find early on in the build are addressed as effectively as they need to be.

For more information on pools and water heights then Google or Bing will provide you with a great deal of information, but don't be afraid to ask the contractors. They should know precisely what they are doing when it comes to building pools for consumers and businesses such as hotels.