Ladybirds are a good idea but they are better for getting rid of aphids and insects that actually live/feed on the plant itself, and there are a couple of problems with using flying predators aswell .
First off they will get toasted if they fly anywhere near your lights ! second you have no guarantee that they will stay in your grow room (unless it's sealed) and of course there is just as much chance that they will stick to your buds as with the fungus gnats.
neem oil is a good deterent but it really stinks ! and it's not a good idea to get that stuff on your buds yuk!.
I had
the worst ever infestation of fungus gnats and moth flies (very similar to gnats but even more annoying!) i used everything: nematodes, gnat off , electric fly killer, sprays and potions they all worked well but the gnats would just come back even more prolific than before.
THen i used the predator mites and within two weeks the gnats were completely gone and did not come back.
i would buy another load of them every 6 months or so just to make sure the gnats did'nt get another foothold.
here's a couple of places that sell natural pest control in UK :
Predator mites:
personally i would rather go to the hydro shop place and get them from there. You can see how expensive they are but if you add up the cost of buying endless fly strips and sprays it will actually work out cheaper in the long run.
I would wait till this grow is done then buy the predator mites and apply them to all your mums and your next crop.
....although you could use them now, then when your plant are down simply transfer a bit of the growing medium to your next lot of plants, the mites will get tranfered to the new pots with the soil/coco or whatever.
they won't crawl onto your buds.
oh BTW sciarid flies ,black flies and fungus gnats are all the same thing just in case you did'nt know :winking0067:
