The lower leaves on the phalaenopsis turn yellow with stains quickly

[cyclone125]

Hi!
I have a problem with phalaenopsis. Lower leaves turn yellow with strains. Not only one, but several of them at once. I noticed this just a couple of days ago and they keep turning yellow quickly.
There is also an weird plaque on the roots.
I have already lost another phalaenopsis with the same symptoms.
Please, see images attached.
What is it and what can I do?
Please, help!
Thank you in advance!

P.S. This is the link to high-resolution images to see better what is going on:

https://i.imgur.com/94i8Czx.jpg
https://i.imgur.com/sIvRfsX.jpg
https://i.imgur.com/pzfKOp4.jpg
https://i.imgur.com/QPLLPv4.jpg

[Shadeflower]

hi cyclone, you need to provide more info as its not easy to identify a problem on a picture alone.

what water, tap, rain osmosis?

what temps day and night and lowest temp received this year?

what light?

how did you fertilize it when, if you were? When was it bought?

[cyclone125]

It was bought about year ago in supermarket on sale in a rather poor condition.
Then it was repotted to good quality bark. Then it has been growing well for almost a whole year. The growth point was damaged, but a lateral shoot began to grow. Watering once a week with boiled water. Temperature 21-24 C (69-75 F) night / day. Stands at the east window with additional warm white LED light for several hours. There has been no fertilization in the last couple of months.

I suspect fungus or bacteria. Perhaps recently the temperature has been slightly lower, and it did not completely dry out between waterings. Thus, the plaque on the roots is a fungus (mold?). But I don't know what to do. Should I put the roots out of bark completely and spray it with аntifungal agent? But the stem seems to be struck as well.
I suppose the yellowed leaves need to be removed anyway?

[Roberta]

First, welcome!

The yellow leaves are probably just old. Let it drop naturally. The crack in the good leaf is just mechanical damage. The pot looks to me like it has poor drainage - you should repot into something a pot that will drain better - personally I like bark, but loosely-packed sphagnum will work too. The goal is "humid air" rather than "wet" in the root zone.

I don't see any purpose in boiling water... best watering practice is to put it under the faucet and let water run through the pot (which flushes "junk" and also pulls air into the root zone) Note that after you repot, you will need to water more often, since the new medium will dry faster. Which is exactly the goal. (Also winter heating reduces the humidity, again leading to faster drying) To determine watering frequency, consider weighing the pot on a kitchen scale or postal scale right after watering, Weigh the next day, etc. When the rate of weight loss decreases (less water to evaporate) it is time to water again. Also with winter, be aware of cold drafts... you probably do not want to have the plant too close to a window.

If you repot into a well-drained pot, I don't think that any treatment is necessary. Just create a healthy environment in the pot a and the plant will take care of the rest.

[cyclone125]

Hi! Thanks for the tips and advice.

Originally Posted by Roberta

First, welcome!

The yellow leaves are probably just old. Let it drop naturally.

I don't think that it is natural old yellowed leaves. This phalaenopsis has 7 big leaves (not counting the lateral shoot). It may be difficult to see it in the photographs, but the two bottom sheets are already almost completely yellow, and three more have begun to turn yellow with yellowed stains.
Do you think that simultaneous yellowing of 5 out of 7 leaves for several days is normal natural process?

I also had another phalaenopsis that has died within a couple of weeks with the same symptoms (completely yellow and withered).

---------- Post added at 10:53 PM ---------- Previous post was at 10:47 PM ----------

This is the link to high-resolution images to see better what is going on:

https://i.imgur.com/94i8Czx.jpg
https://i.imgur.com/sIvRfsX.jpg
https://i.imgur.com/pzfKOp4.jpg
https://i.imgur.com/QPLLPv4.jpg

[Shadeflower]

I don't think it is dying.
I don't think there is anything wrong with the pot.
5 leaves dropping is not normal..

Personally I would still be fertilizing especially if keeping it at 20 degrees, that is summer temps... Phals don't rest. At least warm growing ones don't so if you keep it warm with additional light my motto is to keep on fertilzing it.

Could be as simple as that. Literally.

I'm not a fan of tap water myself and I believe long term it contributes to leaf problems but maybe I am exaggerating, it does depend a lot on the water quality. Some people have soft water and no problems using it. Rain water is just safer imo

[cyclone125]

Originally Posted by Shadeflower

I don't think it is dying.
I don't think there is anything wrong with the pot.
5 leaves dropping is not normal..

Personally I would still be fertilizing especially if keeping it at 20 degrees, that is summer temps... Phals don't rest. At least warm growing ones don't so if you keep it warm with additional light my motto is to keep on fertilzing it.

Could be as simple as that. Literally.

I'm not a fan of tap water myself and I believe long term it contributes to leaf problems but maybe I am exaggerating, it does depend a lot on the water quality. Some people have soft water and no problems using it. Rain water is just safer imo

Ok, thanks for your answer, Shadeflower.

[Shadeflower]

Hope it doesn't lose any more leaves.
Would be great to hear how it does but gl with it