Switch off the pool pump and drain the pool filter
Switch off your pool filter and the pump first on the other hand you need to make sure that the timer is not set so that it won’t turn back on. Well, you might not want the pool pump to switch on while you have disconnect everything else. Remember that if it runs dry, there is a chance of burning out. Take off the drain plug which is in the base of the tank filter so that the water will drain out and this process would take some time.
Detach the multiport valve
You need to detach the pipes or the hoses that connects to the valve. In case, if the valve is toughly plumb to the pipe, you would have to cut off the pipe and fix union fittings. Then as a result of that, you would be able to change the sand. Detach the collar or the clamp which hold the valve that fits to the tank. When you have disconnect them, carefully turn and tug the multiport value to detach it.
Cover up the standpipe
You would find the standpipe which goes to the massive load of old sand. So before you take off the old sand and replace with some new sand you have to cover the cap of the pipe. I hope that you do not want sand to get into your pipe since when you finish doing it and switch it on the sand would end up getting into your pool.
Take away the sand
Take out all the sand using a big cup and dig out all the sand.
Wash the laterals and the tank
Now you might see that filter standpipe having a lot of laterals stick out of it. So use a hose to wash out the remaining sand of the filter. Make sure that you check the laterals and the pipes for any damages or cracks. In case, if there are crack or broke, you need to replace them before putting new sand or else it would end up getting sand into the swimming pool.
Fill half of the tank with water
Before putting the new sand in to the filter, make sure that the standpipe is set, laterals are in place and replace the drain socket on the tank, thereafter fill half of it with water. So this would act as a cushion when the sand falls onto the laterals and would prevent from breaking.
Put the new sand
Make sure that you only use pool filter sand and restrain from using any other sand to fill it. As you are dealing with substantial sandbags, you need to be more careful. According to the size of your tank you might want one or more bags of sand. So take your own time and carefully put the sand without spilling them everywhere. Moreover, you need to cover the standpipe.
Completely fill the tank with water
When you have finish adding sand to the filter, make sure you fill the remaining space of the filter with water. Moreover, restore the valve, multiport, collar and hoses or pipes carefully.
Clean and backwash the pool filter
Before turning the pump or the filter on, make sure that you rotate the multiport valve to do the backwashing. Ready the pump and switch it on and let it backwash for around two minutes or till the sight glass gets clear. Anyhow, this process would help to remove all the dust particles and waste which is in the new sand. After finishing that turn off the pool pump and turn the multiport valve to do the cleaning and thereafter turn the pool pump on once again. Do the cleaning for at least one minute.
Operate the pool filter
Finally you have complete it! Now turn off the pump and turn to the filter and on more turn your pump on. Monitor the pressure meter, whatever the meter indicates, it needs to be the standard operating pressure. So you need to concern about this. When the pressure reduces to ten psi comparing to the standard pressure when operating, you will have to backwash the filter. Through backwashing you will be able to remove all the waste and dirt. But you need to remember that too much of backwash is not appropriate. Use the pressure meter as the indicator to backwash.