I finally compared terrarium drainage layers with and without charcoal

I built two identical 5-gallon terrariums last month, one with a standard gravel and activated charcoal layer and one without any charcoal at all. After just 3 weeks, the no-charcoal one started smelling musty and I found mold forming on the soil surface near the glass. The one with charcoal still looks fresh and clean. Has anyone else noticed a big difference skipping the charcoal step?

2 comments

2 Comments

wilson.emma1mo ago

Oh wow, I never thought one little thing like charcoal could make that much difference... but your experiment really proves it, huh? I've been using charcoal in all my terrariums for years now, but I think a lot of people skip it because they assume it's just a gimmick to sell more supplies. The thing is, charcoal actually absorbs all those extra toxins and odors from rotting plant matter, so without it the whole thing turns into a stinky mold factory. You definitely wanna keep that layer in there if you want your terrarium to last longer than a month.

matthew_wilson461mo ago

Learned that one the hard way. Took months to get the smell out of the room.