question: in normal operation, how much water -- as opposed to sand and air -- does a typical sand filter have in it? Enough water to cover the sand? Water all the way up to the top of the standpipe? I have looked at various instructions and videos and do not see a clear answer. One thing I looked at said that the operating filter "sprays" incoming water onto the sand, implying that there is an air layer above the sand. The deep cleaning video seemed to leave water all the way to the top before starting it back up.
Followup question: after having drained the water from the filter, leaving the old sand, and now wanting to restart the filter, how much if any water should I add before putting the valve back on and starting it up? Thanks
Followup question: after having drained the water from the filter, leaving the old sand, and now wanting to restart the filter, how much if any water should I add before putting the valve back on and starting it up? Thanks