Hmmm, not too familiar with the term "self rising pool". Can't help you there.
For what? Building a cove for a vinyl liner. Adding sand to a sand filter. Building a sand box. For the base of a pool. ????
yes, just sand will let grass grow through your liner. im in the process of getting vermiculite installed in my above ground pool, because grass grew through the liner.
If you are getting sand coming into the pool and have a sand filter you may have to replace worn laterals in the sand filter.
It already is used as pool sand!
Possibly you are in need of new sand or you can go to the pool shop and ask if they have a chemical sand cleaner.
Sand is normally put under the pool liner to create a smoother surface.
Whether or not you need to use sand as a base in laying a sidewalk depends upon what you are laying it with. For example, if you were using bricks, it would be better to use a sand base to prevent the bricks from shifting over time.
Silica sand has glass in it, and it is not to be used in pool filters. You will get the best results when using pool sand.
You will need to level the area under the pool, though. Most suggest using sand to do this.
Need to rephrase question.
If you have a sand filter the laterals in it may be starting to show signs of wear these wil blow sand from the sand filter into the pool when they wear out.
It depends on what you mean by low. You need to check your filter's manual, and see what level it SHOULD be. Lower than that, usually means you are losing sand into the pool (you'll know!) or when you backwash (because the pump is too big for the filter.) If you are losing sand, you need to correct the cause and then add more sand, after you've resolved the problem.