If repairs aren't too large, you might consider doing it yourself. You can read my guide on how you repair pool plaster and my guide for pool plastering, if your pool needs a lot of replastering.
Resurfacing a pool also involves handling many tools most homeowners are not familiar with. It’s also a labor-intensive project that can be risky if you don’t have the know-how. Not to mention, many things can go wrong and cause you to have to redo the entire job.
Cracks invariably appear they can be caused by a chemical imbalance or by UV rays, or even by slight shifts in the soil beneath the pool. The veneer may start to peel. In turn, the cracks collect dirt and algae, and pretty soon you have what looks like a giant birdbath. It may be time to drain and resurface your pool.