Clay pots and growing moldy white substance?

[Ashleyma23]

Hi All,

I have my clay pots for my orchids potted with lava rock and hydroton and I am always getting a moldy white substance around the outside of the pots. When I go to water them I wash the and it feels slimy. Is this mold or what?

Should I unpot?
Should I wash the outer with bleach water rinse?
Or something holistic?

They are all growing well that I don't want to disturb them too much.

[estación seca]

I've never looked at it under a microscope. I've always thought it is the minerals left behind by water evaporating from the clay. You can scrub it off with a plastic pot scrubber.

[Tindomul]

I also think that what you are describing is salt build up from the water and or fertilizer you use. Just be sure to flush your orchid as well since it's media may also have a buildup of salts.

[Ray]

Agreed. It is very fine crystals of minerals dissolved in your irrigation solution that have precipitated upon evaporation of the water. It feels a bit slick when wet, but is crusty when dry.

[Ashleyma23]

Originally Posted by Ray

Agreed. It is very fine crystals of minerals dissolved in your irrigation solution that have precipitated upon evaporation of the water. It feels a bit slick when wet, but is crusty when dry.

I think I had a combo of both salt build up and mold.
THe mold was fuzzy and didn't dry up. I was a bit paranoid since I have them in my room.

I had them over potted in clay pots. And when I imported them the lava rock was very wet. It was more porious then I imagined.

I have since repot them into plastic cups with hydroton for s/h.

I have a question about set up.

I don't have too many orchids, but if I was to buy a small plastic tier greenhouse , what type of light fixture would I buy. It's between a light fixture or a heatmat for the winter time.