Grit vs Perlite?

Some of my young phlox among other things are still in pots and are going to stay in pots in my little pvc covered greenhouse over winter whilst trying to improve my soil. Shelves a bit flimsy so weight could be an issue. Would it be OK to mix no3. with perlite? Sorry I keep asking so many questions but at the moment it feels like I'm faffing everything up.

 

Hi Cindy

Are you trying to inprove the drainage for the phlox and put them into bigger pots but to keep the weight down on your shelves , yes perlite will be fine

Spruce