CREATE TABLE table_68583 ("Frequency" FLOAT, "Callsign" CLOB, "Brand" CLOB, "Format" CLOB, "City of License" CLOB, "Website" CLOB, "Webcast" CLOB)

Name the lowest frequency for brand of radio manantial
SELECT MIN("Frequency") FROM table_68583 WHERE "Brand" = 'radio manantial'
SELECT MIN("Frequency") FROM "table_68583" WHERE "Brand" = 'radio manantial'