Blooms are dying?

[Patrick DiFlorio]

225 gal Ft
4 27gal grow beds (flood & drain)
35 gal sump
Swirl filter

Ammonia 0ppm
Nitrite 0ppm
Nitrate 40ppm
pH 7.7

Look real close at the photo.

The beds appear to be maturing, based on the visible growth in the swirl filter
(Brown algae)(diatoms)

My plants look to be doing fine except that the blooms on squash and zucchini plants keep falling off. No fruit will set.
I have dosed with chelated iron, both in the fish tank, and directly in the beds.

This is a very young system, but what could be causing bloom wilting?

Thanks in advance.

[Patrick DiFlorio]

Here is the photo

[sam]

hi there. i'm a newb for gardening and all.. but I think zucchini flowers are either male or female... so u need to hand pollinate them or depends on bees or butterflies to pollinate ... if its dying, well either its a male flower or unpollinate female flower.

good luck!