How do you extract sand from water?

You need to disconnect the pump and filter from the pool lines first, 2nd if you have you owners manual check to see how much sand you need to have to replace the old sand, if you do not have that info then you need to put the old sand in buckets to figure out how much needs to go back in its always good to have an extra bucket of sand, 3nd remove the bolts from the top of the filter and take the lid off there should be a gasket underneath the top lid try not to tear it if you do get, a new one the torn one will leak, remove the old sand, once you get the old sand out by what ever means meaning using a running hose, you are then ready to put the new sand in. The trick hear is, there should be a seprator that goes inside of the filter to put the sand in the right place, if you do not have this, do not take the filter apart you will only make a mess of the pool, you need this seprator, go to the pool store and get or order one, this seprator goes down inside of the middle of the filter and all you do is pour the sand in around the outer part of the filter until the desired amount of sand is put back into the filter, then remove the seprator, put the gasket back on the top of the filter place some bolts between the top of the lid gasket and filter place the rest of the bolts tighten put the filter and pump and pool lines back together prime the pump just like starting it up at the start of the season make sure you connections are tight and you are not sucking any air.