HCA: Hermit Crab Association

My humidity has been spiking up to 99 at night and in the day, I have to ventilate it with a fan in my room to keep it down. The fan doesn't effect the heat and that stays at 81°f day and night
How can I keep my humidity down?

Sent from my SM-G973U using Tapatalk

High humidity is fine for the crabbies. Mine is in the 90s in both tanks all of the time. The only thing it might cause is more/faster mold growth on food and some objects.

Sent from my Moto G (5) Plus using Tapatalk

Just keep the tank vented a bit.