Pools, Spas and Hot Tubs - Bumps on I.G. pool floor

New I.G. pool installed last year, steel with vinyl liner. bottom of pool was smoothed with a sand/portland cement mixture that hardened- looked like a fairly thin layer. Several spots on the pool bottom feel as though rocks or other pointy objects are pushing up against the liner on the pool floor. Is this normal, or is this something to worry about? I believe I have a 5 or 10 year liner warranty, but would still like to know what is causing this.

Thanks.

It is not a liner issue, it is the bottom. There is either pebbles or rocks not smoothed into the floor when troweled or there was debris left on floor when liner was installed. If very small and not sharp should not be a big issue, if sharp and larger could wear through liner.

I know it's not a liner issue, my point was it is under warranty so if rocks/pebbles wear their way through the liner, I will be covered. Warranty for liner is actually 20 years.

Pool co. was out yesterday to replace a vanquish pop up head in the pool and I asked him about the objects under the liner. He said there is a way to "vaccuum" them to the edge of the pool so they are out of the way, and he will put a note in the file. They are actuall small, and not too sharp. When I swim to the bottom I can feel them with my hand, but never noticed it when stepping on it with my foot. This is probably normal & I never noticed it in other people's pools.