Roots getting white powery film

[ed241]

Help,
The roots of my orchids and the top layer of bark is turning white. I use R.O. water(the tds. meter says 008) I have not fertilized in a long time and I soaked and flushed the pots but it still comes back.
I remove the top layer of bark and the new bark starts turning white.
Also my semi-hydro pots are doing the same thing
thanks
Ed

[King_of_orchid_growing:)]

If you're suggesting you thought it might've been mineral and salt deposits, I'm not sure it is. Mineral and salt deposits are crusty, like when you get a T-shirt wet in salt water and you allow the salt water to dry on the shirt. If you have a pic that would help.

Sounds more like fungus.

If it is, then...More air circulation. Change out medium. Use a fungicide (you gotta ask someone who knows fungicides for this one, be careful). Reduce humidity. Water a bit less.

A pic would go a long way.

[ed241]

here ya go

[King_of_orchid_growing:)]

It's for sure fungal.

[ed241]

I treated with Physan 20 and it actualy seems to have gotten worse.
More of the rocks have turned white

[King_of_orchid_growing:)]

How do you grow your plant? Where do you grow this?

[ed241]

I grow them in my house under a h.i.d. light. All are in semi -hydro except one which is in bark. I have been growing them for several years whith no problem.
I am watering them twice a week now hopping it will flush them out. I had been watering once a week.

[King_of_orchid_growing:)]

Okay, I think I see a humidity tray underneath the pots.

I think you've got too much humidity and too little air circulation. That's a classic condition for growing fungus.

Do you have a fan lightly blowing air around the orchids?

[King_of_orchid_growing:)]

I think the hydroponics medium adds to the moisture too. Perfect growing condition for fungus.

Like I said, try a fan.

[PAorchidman]

try one off those litttle ten dollar computer tower fans and silicon it on the side of the tank just above the humidity tray