What is this powdery stuff

[estación seca]

We get what is called powdery mildew on the undersides of rose leaves growing outside, during cool and dry spring and fall weather. I don't think we're ever humid enough for long enough for humid-growing fungus to attack our outdoor plants. Maybe there's a difference in common names in different parts of the country.

[tellmewhy]

Sorry ChrisAZ
I also have a white stuffs at my mounted Phal. But I grown out side. Don't know what to do with this.i used hydrogen peroxide yesterday but today the white thing still there?

[estación seca]

Originally Posted by tellmewhy

Sorry ChrisAZ
I also have a white stuffs at my mounted Phal. But I grown out side. Don't know what to do with this.i used hydrogen peroxide yesterday but today the white thing still there?

Attachment 122856

I can't enlarge the photo much, but I wonder whether that's spider webbing?

[tellmewhy]

Originally Posted by estación seca

I can't enlarge the photo much, but I wonder whether that's spider webbing?

No, it not spider webbing. It grown on every crack of the wood. Here another photo.

[PaphMadMan]

Algae should be pretty well controlled by Physan, pretty safe stuff for plants and humans, but not appropriate around amphibians. I agree that hydrogen peroxide would be a better choice in the vivarium. It can even be used to supply extra oxygen for fish or fish eggs in closed transport containers. It does break down to water and oxygen pretty quickly. Still, I wouldn't let it contact the frogs. If you can take them out and return them some hours after treatment there will be no residue.