Sprouting barely for feeding to horses

I have been experimenting with barley sprouting and have overcome mold, rot, bugs, but one thing I am really battling with is that seeds are sprouting at different rates in the same tray. So after day 4 I have one side of the tray with beautifull green barley leaves and the other side with just little shoots. I am growing hydroponically in a temperature controlled /ventilated chamber with seed trays and water sprayers - how can I get my barley to sprout uniformally Tweet