WHy Does My SOil Keep Popping Up?

day after day my soil wont stay down. i'm using organic soil with perlite in a plastic cup suggestions?

use it to your advantage... obviously when you water, the soil expands... and as it dries it settles back down. Use it as a gauge to tell ya when to water. If the soil isn't pumping out of the cup, and your plants aren't dieing, I wouldn't worry about it.
Nim

too much perlite?

Yes, the suggestion is to use a heavier planting mix next time.

If you put a pot into a tray with 1" of water in the tray does it soak that water up after an hour or so, to where you can see the top is wet? If it does then that's the way to water from now on until you change media when you transplant.