Smallpooldad, your advice on stains (and Marie's) helped me with a pool I had to treat a few weeks ago, so I definately owe you an answer. I don't know of any light that can't be removed with the water at operational level, most installers realise that the bulb may need to be changed at some point and leave enough cord to bring it up to the deck, even if they haven't, there should still be enough room to get it out of the niche enough to clean the niche. Hopes this partially repays my 'knowledge debt' to you