No drainage hole means excess water has nowhere to leave — roots sit in anaerobic muck if you water like a houseplant pot.
A false bottom of LECA, gravel or clay pebbles stores overflow below the root zone as a temporary reservoir and visible oops gauge.
Charcoal is a helper, not a flood licence. Never use barbecue briquettes. More pebbles never replaces restraint with the spray bottle.
Some modern bioactive keepers debate drainage layers in large vivaria with deep soil — for beginner sealed jars, a simple false bottom remains the safer teaching default.
