Lisa: I've been using the OVE worm tea for nearly six months. I foiliar spray a couple times a week. The insecticidal properties seem to be working. Not sure if it's been good luck or the worm tea, but I've not had any pests.
Since it's a bit costly, I only use the tea for complete watering about once or twice a month. My dendrobiums especially like the worm tea. Not sure if I can attest to terrific growth due to use of the tea because we're in our growing season - so maybe they're growing well due to the worm tea, or maybe just because it's their season to grow. Time will tell.
p.s. Just use the converter link below to recalculate to metrics. It's much faster than having to learn a whole new system.
http://www.digitaldutch.com/unitconverter/