Assertion: sand filter | /r/HasProperty | backwashed
Facets:
value: once a month
type: TEMPORAL
Source sentences:
text: As with the D.E. filter, your sand filter will have to be backwashed when the gauge shows 8-10 psi over the starting value.
text: Sand filters become clogged with floc or bioclogged after a period in use and they are then backwashed or pressure washed to remove the floc.
text: Sand filters become clogged with floc or bioclogged after a period in use and they are then backwashed or pressure washed to remove the floc.
text: Sand filters, however, can be backwashed once a month and are typically torn down two times per year.