Cinnamon. Natural fungicide. If they have nothing to eat, they will die off.

Diatomaceous earth. The food grade kind is safe for humans, animals, everything but bugs with exoskeletons.

Try to let your plants dry out. They thrive at the top of your soil and that plus cinnamon can be enough. I have been using both and they're drastically reduced in number. Try fly strips (they come in yellow cards you can put near the pot rims or ones that come out in a ribbon).

i try and let my soil dry out as much as possible... i think the problem is that i mist my hoyas probably once or twice a day, which must keep the top layer of soil moist... so i guess what im gonna have to do is stop misting for a while... my plants wont like it but im sick of all these gnats...

Misting is really for the gardener's benefit. The misting really only raises humidity for maybe 5 minutes. You can try pebble trays or a humidifier if you're really that worried about humidity.

Some of us here tend to think that fungus gnats come from overwatering. Most of my Hoyas are on pebble trays, I don't mist & they're fine.

One thing that I have done that seems to help is to get some carnivorous plants. I have a venus fly trap and a sundew. The fly trap gets the bigger bugs and the sundew gets those pesky little fungus gnats. I rarely see gnats anymore.

Mel

I agree that your plants will be fine without misting and allowed to dry out well for a round. Occasionally I get a batch of gnats, but I completely ignore them because they are always dead by the next time I water. The Hoya watering schedule simply isn't gnat friendly, so you don't have to sweat this pest.

ok cool... i do let my plants dry out pretty well... but i think the soil i ended up buying was infested, along with the misting that must have been keeping the top of the soil moist must have helped the little nasties... ill stop misting and i think everything should be fine. thanks everyone!