what is this and how I cure it?

[christianrodher]

what are those "purple" spots appearing in many of my orchids? How do i cure it?

[rbarata]

Not sure, I can't see well with those pics but read this, especially the second answer.
Probaly your plant is "tanned" from high light.

[christianrodher]

Originally Posted by rbarata

Not sure, I can't see well with those pics but read this, especially the second answer.
Probaly your plant is "tanned" from high light.

i got a close up in one of my low light ones

[jkofferdahl]

It looks to me like overexposure to sunlight.

[Sharon's Sheepdogs]

If the tip of that orchid leaf has taken on a red/purplish color, I agree it's excessive light. I grow under t5 HO lights and every Potinara I have develops this problem beginning on the leaf tips.They can't handle the same amount of light as my other orchids.

The red/purple hue the leaves are taking on indicates the orchid is receiving the peak amount of light it can withstand. The next step will be sunburn and once that type of damage occurs, the leaf will remain permanently damaged. Pull the orchid back from the light some and see if that doesn't help. If this is the problem, the leaf tips usually return to their normal color.

[rbarata]

In plants with requirements of high light intensities this is considered a good sign.
You must check what are the light requirements of your orchids.

[MattWoelfsen]

Originally Posted by rbarata

In plants with requirements of high light intensities this is considered a good sign.

You must check what are the light requirements of your orchids.

Thank you for posting that link and your comment here. The red pigmentation in these leaves is anthocyanin, which is loosely analogous to tanning in human beings. This pigmentation is the plant's response to harmful ultraviolet radiation.

[jkofferdahl]

While some purplish coloration on some leaves is a good sign, these leaves don't look like they're appreciating it. I'd suggest getting them some shade.

[Sharon's Sheepdogs]

I agree with the previous post. Yes, a little red tinge is healthy because it means the orchid is definitely receiving the amount of light required. However, if the reddening is to the degree where the leaf appears to becoming damaged, I'd move it to where there is less light intensity. It's a fine line between suntan and sunburn.