Questions about predatory nematodes and if safe with plants

Looking to pick up some predatory nematodes this week. Have a bit of fungus gnats flying around and they are very annoying.

Do these little worms affect the plants negatively?

Any specific nematodes I should look for?

Im completely new to using insects to take out insect and ladybugs are out of the question for indoor.

Thanks guys

I don't know about the nematodes so will be interested in answers you get.

One other option that worked well for me with gnats was BT (Bacillus Thruingiensis) sold under various trade names. Mosquito Bits is the name of the brand I used, but think there are many. Here is the info on it from Wikipedea:

Spores and crystalline insecticidal proteins produced by B. thuringiensis have been used to control insect pests since the 1920s and are often applied as liquid sprays.[SUP][19][/SUP] They are now used as specific insecticides under trade names such as DiPel and Thuricide. Because of their specificity, these pesticides are regarded as environmentally friendly, with little or no effect on humans, wildlife, pollinators, and most other beneficial insects and are used in Organic farming,[SUP][20][/SUP] however the manuals for these products do contain many environmental and human health warnings,[SUP][21][/SUP][SUP][22][/SUP] and a 2012 European regulatory peer review of 5 approved strains found that while there is data to support some claims of low toxicity to humans and the environment, there is insufficient data to justify many of these claims.[SUP][23][/SUP]
Bacillus thuringiensis serovar israelensis, a strain of B. thuringiensis is widely used as a larvicide against mosquito larvae, where it is also considered an environmentally friendly method of mosquito control.[SUP][24][/SUP]