Bumps under vinyl liner?

[beantownace]

Hello all. We have our first pool from a house we bought and I have fixed multiple leaks so far some that were dime size holes in the deep end of the liner. Now on that end near the main drain I am seeing raised hard like nickel size bumps that I am worried any pressure, brushing etc. will cause another hole. Planning on replacing the liner maybe next year. Any idea what this signifies the bumps and could the other punctures that I patched caused that?

Thanks all.

 

[Casey]

Welcome. The bumps are more than likely small rocks or pebbles that resulted from a poor job on the pool base. They only way to fix it is to remove the liner, remove the base and lay a new base of vermiculite or what not.