Hi all. This is probably a very noobish question, but I'm looking for a good source for some perlite to add to the potting mix I'm using for my plants. All I can find locally is Miracle Grow perlite that has their own ferts mixed in, but would prefer just straight perlite with no added ferts. I've tried looking online but as a fairly new grower I'm confused by the different grades and prices. Any help for a grower looking for something to help with aeration and drainage is appreciated.