Beneficial Nematodes

So I started using these guys to fight off a root aphid issue but im wondering will watering with synthetic nutrients kill off these lil guys?

It most likely will kill them at some point. With synthetics there is a lot of salt involved. It causes the soil to dry way out and can suck the life out of them. Leaving behind dried up dead nematodes. Just like eating salty foods makes you thirsty.