It depends on how many gallons the pool holds.
Draining the water from the "pump" (I'm assuming you mean the filter) should only take a few minutes. How long it would take to drain the water in the pool down to the winterization level would depend on the size of your pool and the pump you are using.
Overnight or same day with the proper size equipment and pump or pumps. K
how long did it take to build the in- pool ground
it depends on how big the pool is
Syphon - ensure the bottom of the pipe is lower than the top, suck the water through and it will keep flowing. A standard 3/4" hose will take a LONG time to drain a large pool, but you can use multiple hoses...
This is one of those questions that has no real answer. You drain a pool by pumping out the water so the bigger your pump, the less time it takes. Your standard olympic sized pool holds 660,000 US Gal. so take that number, divide it by your pumping capacity and that will give you the time.
The intake hose on a pool is typically used during cleaning. It is usually located inside the skimmer area. The drain at the bottom of the pool can also take in water.
lets just say alot
It depends on your water chemistry, if you need to drain an in-ground pool every few years to recycle the water. If your cyanuric acid level is out of control you should. If you keep it balanced there should be no need to drain it and refill. Take your water to a pool professional to see where your chemistry is at.
The valve for the main drain on older pools would be located at or on the equipment pad. You will most likely need a pool tech who knows how to plumb pool equipment to have it changed out. On the other hand if you mean replacing a broken or loose main drain grate then you would have to take the loose or broken grate to your local pool store for an updated version replacement. They will advise from there. k
Tampons aren't going to be used to drain a pool, obviously. Tampons are for managing menstrual flow, not for draining a swimming pool. If you were wanting to guess how many tampons would be needed, well that would depend on the pool size and the tampon absorbency!