Hey there friend.
Hubby and I are having a helluva time trying to figure out this pool stuff.
How the hell to you backwash the thing?
There should be a handle you turn to the backwash postion. Push down on the handle and turn it to the right notch, let it flow a minute or so, and return it to regular filtering.
Do you have a sand or DE (diatomaceous earth - white powder) filter? Either way, the process is the same, but you may want to recharge the DE a little if you backwash it hard.
If you can find a make # model, i'll be able to explain it a lot better.
Are you using chlorine or a substitute stuff?