Regardless of the position of any tiles on the pool wall The water level should be about 3 or 4 inches / 75-100mm above the top of the skimmer vein before the skimmer basket or at such a level that it does not suck air through the skimmer. of you have a suction side floating pool skimmer you can let it get as high as you like and as long as it is sealed properly as low as you like.
The water level needs to be maintained at the middle of the skimmer opening or center of the tile line.
To replace the decorative tile border on a concrete pool, the pool will have to be drained. The old tile needs to be taken off and a new tile with waterproof grout or concrete can be installed. The pool should dry for a week or so, before it is refilled.
No. The tile resisist a water line stain. While paint does not.
No the pool doesn't "have" to be drained. Are you replacing all the tile or just making a repair? Small repairs can easily be done by lowering the waterline to just below the tile. There are also new methods of cleaning tile to restore it to near it's original look. If you are changing the tile your tile setter will probably drain the water.
One way would be to install drain tile in the yard around the pool deck to carry excess ground water away from the pool.
It is not likely, but it depends on what material the walls are made out of. Mud, probably not, but tile yes.
Use a phosphate remover in the water and this will dissolve and return the oils back to its natural state. This will control all oils in the water and clean tile water lines in a pool.
A water proof tile adhesive, available at your local hardware store.
You are not cleaning the tile or water line each week with a tile cleaning brush and pole. You are not maintaining water quality and sanitation requirements. You are not shocking the pool either with liquid or other shock treatment or both often enough. Neglect? If it is on the tile line it is also in the pool and equipment and nooks and crannies ~ you just can't see it yet. You, I would presume, are also not maintaining your pH or Total Alkalinity. k
Yes, Water should be replaced to normal operating level ,Which would be halfway up the opening of your Skimmers. Normally Center of tile line On 6 Inch tile bands or 3" below the bottom of your Coping.
The traditional method uses sand or glass beads. Some cleaning companies use a media that is softer than the tile to avoid damage to the surface. Specially processed sodium bicarbonate (baking soda) and hydrated magnesium sulphate (epson salts) are used quite frequently for cleaning pool tile without damaging the tile. Both of these products are not recyclable and are cleaned by dissolving in water. Care must be taken with sodium bicarbonate because it can damage landscaping if not used properly. Surface Renewal Pool Tile Cleaning uses both glass bead and magnesium sulfate to clean pool tile. You can not bead blast glass pool tile without etching so the use magnesium sulfate to clean glass pool tile is a must. On standard ceramic pool tile glass bead blasting is sufficient due to the high cost of using magnesium sulfate as long as it is done at a low pressure.
tile Definitely tile!