Just purchased a hawkeye spa.... schooner - has balboa vs500z spa pack and (1) AO Smith 3.0 hp pump (not bhp). Wired 240 volts and spa has 385 gallons. When purchased we received 2 filters.... 1. FC-2390 50 sq ft filter and 2. FC-2375 25 sq ft filter.... have been using 50 sq ft filter and cleaned twice since purchase..... (hawkeye replacement filter from websites seems to be the 50 sq ft filter)..... It is extremely hard to clean because of 50 sq feet of material around filter. The 25 sq ft filter seems a lot easier to clean between pleats. It seems to me the 25 sq ft filter would be less strain on the pump as long as I clean the filter (monthly) and replace about every 6 months...... would like to know pros and cons of using a filter with half the material..... 25 sq ft is bout $8 cheaper....... any info would be appreciated..................... 