How do I get more female flowers on Zucchini

[saila]

Hi All
I have had my aquaponics system running since January. Most of the plants (tomatoes, eggplants, basil, pawpaw, spinach, lettuce) are doing well. The zucchini plants look healthy and have plently of male flowers - but have only had a couple of female flowers - this there anything I can do to get more female flowers? I have tried adding iron, eco rose and seasol (at different times).
Kathy

[terryd]

We grew zuchinis in the ground and we got the opposite , all female flower,someone said they thought we got a bad batch.

[organicusrex]

Were they hybrids or heirloom open pollinator types?

[terryd]

I dont know i bought them from a nursery.

[organicusrex]

Other than bad seed stock at the nursery being the cause the only other possibility would have to be a phosphorus deficiency affecting blossom set.

Early on in young squash I've seen more male flowers than female but they would normalize in a short period of time.