DO NOT knowingly allow your pool to leak.
That sentence is worth repeating – DO NOT knowingly allow your pool to leak.
If you allow your pool to leak, the water loss will be the least of your problems, because when a pool leaks, excessive soil saturation, ground water (accumulation), undermining and erosion of the soil under and around your pool, as well as major problems to the pool shell and structure will result. And, the cost for their required pool repairs will be far more – far more – expensive than the initial cost would have been for leak detection and repairs to eliminate not only the leak once it was noticed, but also the real potential for far greater problems and expenses.
If your pool leaks, then contact a local pool professional that is trained and experienced in the overall field of leak detection and repairs.
If the underground plumbing pipes are the leak source and you ultimately decide to re-pipe the entire pool with all new pipes, then the pipe size (diameter) as well as your pump and filter should all be upgraded and properly-sized at the same time. While various pool chemicals (such as your chosen sanitizer, shock, the water balancers, and some maintenance chemicals) are certainly required to maintain water chemistry (and therefore assist with water clarity), proper circulation and filtration are the real solution to optimal water clarity. However, proper circulation and filtration can only be accomplished when the pipe sizes (diameters) as well as the pump and filter are all properly-sized to work together, based on the number of gallons of water in your pool.
You can read the Pool Manual for additional information about leak troubleshooting, detection and repairs.