Might be night temperature- that's a little low for strawberries. University of Arizona recommends night temps 10-12 C. Also, what sort of nutes are you using? Many nutes are 3-part, and have different concentrations for growth and flower phases. Do you know what cultivar your strawberries are? Also, many strawberry enthusiasts say to pinch off the runners to get bigger berries. During fruit set, you might up your EC to 2.1 or 2.2 as well for better results. 8 hrs of sunlight might be on the low side too, but I don't guess you can do much about that outdoors.

thanks for the advice- Actually i underplayed night temp & sunshine. Temp is around 11 & and sunshine now would be close to 10. I have been taking off the runners. Maybe increasing EC as you say might help. Good thing about hydroponics is that you can change your nutrients & PH instantly.

One of the draw backs is the conflicting information as to what is best PH & EC.

Trial & error is probably the best solution.

Once again thanks for your feedback.

p.s. I live in Sub tropical area in OZ