I lived and shot on Oahu for 8 years...never needed a humidity solution. I lived and shot in Okinawa and the Philippines as well--where I did need a humidity solution.
Trying to deal with humidity if you don't really have a humidity problem is an unnecessary complication in your life, and fooling with silica gel is too much trouble as a lifetime humidity solution. You have to do silica gel right--every day, all the time for the rest of your life--or you're as likely to cause the problem as to solve it.
This is the thing about fungus: It requires 24 straight hours of >70% relative humidity to grow. If you consistently break that cycle, never give it 24 hours of >70% relative humidity, fungus will never be a problem.
So first, go to a home store and buy three inexpensive hygrometers to make sure you have a problem in your home and where in your home the problem is. Get three of them because you want at least two to agree.
Humidity travels with air movement, so humidity levels will vary in a house and even within a room. It will tend to be higher in "dead air" spaces in a room, such as near the floor in the corners. Check the places you'd store your equipment.
If you have home air conditioning, that should basically solve the problem. If you live on the windward side without aircon, you'll probably have to find a room with good airflow. No closets.
Also: Do not store your equipment in a bag or case. Those will become humidors in themselves...and probably why you have fungus now. Remember that humidity moves with the air, so you need air movement if the air is basically below 70% relative humidity. Even if you have aircon, you have to store your equipment where it's actually exposed to the conditioned air. I keep mine on shelves with clean cloths draped over them to keep off dust.
If you have no place in your home where you can store your equipment at less >70% relative humidity, then look into a dry box--as I said, silica gel is too much trouble for a lifetime solution.
All a dry box is going to do is provide a mild warmth that drives down the relative humidity in the box. Back when I lived in Okinawa and the Philippines--before commercial dry boxes were within affordability--I DIY-ed my own by mounting a 20-watt incandescent light in a kitchen cabinet. The science is that simple.