>>3225243>>3225320>>3225379>>3225445Something that has flushing fungi will spread spores all over. Meaning the fresh spore count will rise. Old spores are already there and still viable with it without new spores being spread around. That's just life.
The best course of action is to reduce the favorability for spore growth. The best way to do that is by lowering the humidity. Sunlight/UVs can help or make things worse depending on too many factors to go through. Most people use UV filters to protect their lenses so it is a moot point. Thus, lowering humidity is the best thing you can do.
To lower humidity you'll need packs of silica gel. Specifically the kind that you can pop into an oven, heat, and remove the stored moisture so you can reuse them. These things are 1 time use only before they need to be "recharged." You use them in completely air-tight containers. You put your lens into the container with the recharged silica gel packs and seal it up air tight. The silica gel pack will remove the moisture from the air and prevent mold spores from growing and ruining your optics. You will need to put in enough silica gel packs to remove enough moisture in the air. So, you need to do some calculating for that. There are online calculators and methods to show you how to do all this.
Here's the kicker. The instant you pop the seal on your air-tight container you'll need to put in fresh silica gel packs, because you just let in all new moisture-containing air and your old packs are too full to take in more. So, to save money, get the kind like in this image or open up packs from other things and put them into your own perforated tin for recharging in your oven. Getting the colored kind of silica gel helps you determine if the packs need to be recharged or not; blue turns to pink/red when full.
