One of the trickiest things to houseplants, soil in particular, are little pests like Fungas Gnats. They are small larvae that live in the soil of houseplants, especially where humidity and moisture are high, and cause damage to the plant's roots. The non-biting adult gnats can become a flying nuisance and are usually seen flying around house plants or near a wind
There are several different things that will help you get rid of those gnats! Sprinkle Cinnamon on new seedlings that may have a gnat problem, or Diatomaceous Earth onto the top of the soil around the base of infected houseplants will help. You can also use DE in your premixed potting soil, to help rid the soil of gnats right away. And sticky traps are great to catch adults flying around the plants, although they are a bit displeasing to look at.
But what about prevention of Fungas Gnats as a whole? Well, yes. It is possible. One of the things we recommend for a preventative measure, is to keep a Mosquito Dunk in a tea bag and allow it to soak in your reservoir. Something like a 10 Gallon bucket with a fish tank air puck in the bottom is great to help dissipate any chlorine from the water. Add in your Mosquito Dunk, and allow it to soak for a few hours before watering your plants. The dunk itself is good to use several times, and is completely safe to use on your houseplants.
'Mosquito Dunks, which is a registered trademark of Summit Chemical Co., are made almost exclusively out of a naturally occurring soil bacteria called Bacillus Thuringiensis. Mosquito Dunks work by gradually releasing their natural larvicide in the water they’re in. The larvae then simply feed on the B.T.I. Larvicide and die from it in a matter of hours. And it’s undeniably clear that Mosquito Dunks work perfectly against all 2,500 different species of mosquito larvae, as well as on insects like fungus gnats and black flies. However, there is zero evidence that it works against other creatures, including other insects and bugs. So if you’re worried that you might hurt your local bee, dragonfly, ladybug or other beneficial insect population, then there is no reason to be concerned about that.'