How much money to keep in a current account?

AMALGAMATED Bank 8 American Bank of Oklahoma 7 Bank of Clarkson 5 BANK OF ELK RIVER 9 CITIZENS State Bank 5 DR Bank 17 EntreBank 8 Farmers Savings Bank & Trust 2 First & Farmers National Bank 6 First Eagle Bank 12 First National Bank of Gillette 6 First Security Bank & Trust 2 Jones Bank 10 LifeStore Bank 5 MARQUETTE Bank 14 Mountain Valley Bank 4 PEOPLES State Bank 9 State Bank of Downs 2 TOWNEBANK 12 VALLIANCE Bank 6