Just a heads up vermiculite is banned in many regions due to it's dust and material makeup being Carcinogenic. Highly recommend you discontinue use of it. Perlite does same thing without the high cancer risk.
In the 90s quite a bit of vermiculite was contaminated with asbestos. The town of Libby, Montana which supplied 80% of the world's vermiculite at the time is an asbestos ridden hell hole. Besides the asbestos there were other cancer causing minerals in the stuff. The mining company knowingly kept selling the stuff and poisoning their own employees.
Pure vermiculite does not contain asbestos and is non toxic, safe to use and works great. Just make sure you're getting the good stuff and the package doesn't say 'mined in Libby, MT.'