What i do is soak my barley once in my tub for about 2-3 hours...then i drain, let sit till next day, give it another ~15 min soak, then again next day...until the acrospires (the shoot that would become the plant) is stuck out of about 20% of the kernels..., then i dry it, with a box fan...then kiln in my oven i modded with a 200ohm resistor to go low at ~150f for 12 hours...then deculm it..(do you deculm your malt?)
if you've got a lot of green rootlets maybe that's the problem?
another issue i could see is, my malt stops growing if i don't water it every day...how long do you let the acrospires get?