leaking pool how to find leak?

[jnjhoward1]

pool has been slowly rising(2" over 4 years) on one end. pool has never leaked and is now for the past 2 weeks started leaking. its still above the returns and light but below the skimmer. its a slow leak. so i am going to see how far she goes. any ideas on pressurizing lines to check them. how to basically would be apreciated. thanks JAKE
ps can a pool be leveled