What is this?

[DabberD0]

It just happened in the last 4 days

 

[jondamon]

It just happened in the last 4 days

Did you spray them with anything?

Looks a lot like powdery mildew!

 

[DabberD0]

It just happened in the last 4 days

It looks like mildew so what do I do

 

[DabberD0]

I didn't spray but noticed a rise in humidity

 

[jondamon]

I didn't spray but noticed a rise in humidity

First things first is look for something that you can use to stop it.

Secondly you need to sort out your humidity.

Either you need to extract more air, move more air within the area, or dehumidify the area.

 

[DabberD0]

I'm completely sanitizing another room 3 36 in filter 10 fan out 1 10 in in with multiple oscillating fans should I do anything to the plants before moving

 

[jondamon]

I'm completely sanitizing another room 3 36 in filter 10 fan out 1 10 in in with multiple oscillating fans should I do anything to the plants before moving

Yes you need to treat the mildew or it will just spread further in the other room.