public void deleteUntil(Date removeUntil) {
logger.info("Deleting tweets older than " + removeUntil);
NotFilterBuilder notPersistentFilter = FilterBuilders.notFilter(FilterBuilders.existsFilter(UPDATE_DT));
FilterBuilder fewRetweetsFilter = FilterBuilders.rangeFilter(RT_COUNT).lt(100).includeUpper(false);
RangeFilterBuilder tooOldFilter = FilterBuilders.rangeFilter(DATE);
tooOldFilter.lte(removeUntil);
FilterBuilder filter = FilterBuilders.andFilter(tooOldFilter,
notPersistentFilter, fewRetweetsFilter);
client.prepareDeleteByQuery(getIndexName()).setTypes(getIndexType()).
setQuery(QueryBuilders.filteredQuery(QueryBuilders.matchAllQuery(), filter)).