The current ALES and F5J type sailplanes are slightly larger but average around 65 oz RTF. We usually do not start adding ballast until the wind hits about 15 mph. My ALES sailplane weighs 80 oz and I have never added ballast and have flown in 25 mph winds. I think yours is a bit heavy to start with but you also have more fuselage surface drag. Your not really going to be very competitive with what you have so I would say no to any ballast and suggest you just fly it as best you can and have fun.