Why vaccinate adults against hepatitis B? Hepatitis B can lead to cirrhosis, liver cancer and death. Hepatitis B is incurable. Up to 1.4 million Americans have chronic HBV infection. Hepatitis B is 50 to 100 times more infectious than HIV.
Re: Pool about to overflow from heavy rain dunno of this works, but try this: put one end of a hose in the pool, the other in a lower part of the garden. Now you need to suck on the hose (the side outside the pool) untill water starts running, normaly, the water will drain.
To increase calcium hardness you'll need calcium chloride. You can swim 2 hours after adding, but if you can, allow for one full turn-over of the water. A turn-over is a full and complete filtration of all of the swimming pool water, normally about 10 hours. This is why you'll want to make any adjustments at night.