I have been using Pro Mix HP, for over 30 years and have never ever gotten bugs, Not saying it can't happen but it has never happened to my grow, The only time I have had a problem is when I took a clone from a friend, and it looked great with the naked eye. turns out it had the dreaded Spider Mites. took a year to get rid of them little SOBs, A good thing to use in your Grow room is Cedar, My room is all Cedar Bugs just don't like it so I was my walls with plain water and let it run all over the tables and I have not had a problem with and bugs KNOCK KNOCK KNOCK on wood

Good luck Hope you get rid of what ever pests you have. Do not let anyone in your room and always go into your room with Clean shoes and cloths, Pests can be carried in by a variety or ways.