Just want to say anyone else who is thinking of using nothing but perlite to watch out for the big brand bags. I noticed that they are starting to include their salt based ferts in with the perlite itself now. Makes absolutely no sense considering most people would couple it with the same brand of soil, which in most cases contains even more of those salt based ferts. Talk about setting people up to burn their house plants. If you think MJ can be a bit touchy you should see what else people like to keep in their households. MJ has a cast iron stomache compared to many other plants.