Rove beetles, green/brown lacewings and ladybugs all eat the shit out of aphids. Soap and water will put a dent in them too. A buddy had a 12 light grow so infested you couldn't see the stems and he beat them with no pesticides at all. Used all of the above methods, and it's been a year and no sign of them.
Rove beetles are the tits when it comes to pest control, they eat everything. I run no till and don't even bother with neem or karanja anymore. The only downside is when they run out of stuff to eat, they forage around in the canopy and get stuck to the trichome.