yellow leaf

[airdalecv66]

Hi, new to forum, greenhouse (fully hydroponic) is 40' X 90' x 25' peak roof, with 850 month old tomato's. starting to show slight signs of 'yellow' leaf on some of the plants, research indicates lack of iron ? also doing self pollination, would blue nose fly do a better job than 100 bumble bee's ?

Thanks for any and all idea's.


https://www.facebook.com/pages/Seren...34767976548426