If your pool is round or oval, multiply the diameter (one direction) times
the diameter (other direction) times average depth and then multiply by 5.9
to get the total water volume in gallons.
18*18*4*5.9 = 7646.4
If there is a pool store in your area, take a sample of the water in for
testing. If no local source is available, you should test the levels
yourself to ensure that you are not already "growing" anything. My local
pool store performs this test at no charge. Unfortunately, since they are
the only store in the area, their prices on many things are outrageous so I
use waterwarehouse for many of my supplies. At
http://www.waterwarehouse.com/subcategory.asp?dept 0 there is a
winterizing kit for up to 7500 gal. for $17.99. Each kit contains a winter
control algae fighter, stain removing metal out, slow dissolving winter
oxidizing tablets, specially formulated non-chlorinated shock, and complete
winterizing instruction guide.
Winterizing tips available at http://pool-information.com/winter.html
We just bought a house with an above ground pool that is 18 feet across and
48 inches high. It has not been opened this year and with winter almost
upon us I plan on leaving it closed until summer. Does anyone have any idea
how many gallons this may hold. It has been drained a bit for the winter
but I would like to shock it/treat it to get through the winter again. Any
suggestions as to what I should put in? Bleach, shock, etc? I know very
little about pools so I appreciate your help.