This is likely a difficult question to answer, but given all the expertise on this board I thought I would throw this out there in case anyone has some insight. I have a house under contract to purchase right now, which has an existing pool that was built in 1983. The pool is concrete, though as it is built on a hillside, half the pool is in ground, half the pool shell is exposed under the deck that wraps around it. Anyway, we had a house inspector take a look at the pool and he found a number of small issues, most of which do not overly concern me, though one does, since I am not sure precisely what it means. The inspection report says he found some efflorescence on a portion of the exposed concrete shell. I have no clue what the implication of this is and the inspector merely advises me to have a pool company take a look, which I am unable to do until after the option period ends. I am including the pic I have of the situation, which is not the largest or the best quality, but hopefully helps illustrate the issue. My hunch is that the pool may need to be replastered, though I am hoping that's wrong. Any thoughts?