We had our pebble tec pool emptied and refilled last week, this morning i woke up and found a half dollar sized chunk missing from the bottom of the pool. Contacted the pool company that emptied and balanced the chemicals but sounds like they may be closed on Saturday. Is this something we can patch with the pool full still or are we going to have to drain and refill again to fix the issue? Is it a coincidence that we are just now seeing this type of issue or could this been caused by the empty/refill?