BKF Capital Group Inc. is again seeking to take over Qualstar Corp., a Simi Valley manufacturer of data tape storage products. The Boca Raton, Fla.-based investment firm notified Qualstar if its intention to put up seven board candidates for consideration at the company’s upcoming annual meeting. A date for that meeting has not yet been set. BKF Chief Executive Steven Bronson has twice before tried to gain control of struggling Qualstar, which also makes power supply products. BKF is the second largest shareholder in Qualstar with a stake of about 18 percent. Qualstar Chief Executive Larry Firestone called Bronson’s latest bid a “wasteful distraction.” “The previous failed attempts by Mr. Bronson and BKF Capital to take control of Qualstar have forced our board and management team to devote significant resources to protect the interests of all shareholders, when these resources could have been better devoted to our ongoing efforts to transform Qualstar,” Firestone said in a prepared statement. In January, Bronson made an offer to buy 3 million shares of Qualstar but later withdrew it after the Qualstar board adopted a “poison pill” provision to protect the company. A year ago, Bronson put up a slate of board of director candidates who failed to be elected. Qualstar has lost $6.92 million on $9.7 million of revenue in the first three quarters of this fiscal year. It lost $4.1 million on revenue of $17.1 million in the fiscal year ended June 29, 2012. Shares of Qualstar closed Thursday down 3 cents or 2 percent to $1.62 in trading on the Nasdaq.