Our pool just decided to do a back wash on its on this morning. Looked out and the water was at an alarmingly low point in the pool.
Thanks for the question Pam
When you backwash the filter you're going to lose water. This is normal as the dirt from the filter is being expelled from the filter. You should only backwash either for 2 minutes or so, or until the water runs clear out of the backwash hose.
Anymore than that and you'll lose too much water and possibly sand, if you have a sand filter. With a normal backwash you'll lose about 200 gallons, or about 600 litres.
The best remedy is to reduce the backwash time to 2 minutes or until the water runs clear. If you backwash too long, simply top the pool off with water, 1/3 - 1/2 up from the skimmer.