Yellow spots on oncidium twinkle red leaves
 

Hello again, my lovely orchid friends. This is adrita again from siliguri , india. So I have a twinkle red which has 4 spikes in various stages of development ( YAY ME!) . But today on a closer inspection of the orchid, I found few yellow spots developing on the leaves. They are not oozy, absolutely normal in texture. Just the colour is different!! Is it normal? Should I worry about it? Should I apply some fungicide?

Hi,
we would need a picture to decide if it is a problem or not but based on the fact it is producing 4 flower spikes I'd say it is happy and that saps energy out of the plant.
This is a good time to up the fertilizer just a fraction to support the growth of the flower spikes. If you don't feed it a little then it will start recycling lower leaves for nutrients.

Just please do not start pouring lots of fertilizer on. Orchids need tiny tiny amounts so even though it can benefit from a little you can easily feed too much and cause damage.

If you lose a lower leaf or two that is nothing to worry about and usually does happen when the plant flowers. Ideally you want to avoid the plant shedding too many with proper care but don't worry about 1 or 2. Feed it a little and see how things go. Although the spike takes a couple of months to develop that isn't that much time to get a few feeds in without overfeeding it at any time.

Are you familiar with how much to fertilize the orchids?

I'd aim for 300ppm for the next 2 months if it helps. That to me is on the higher end for a small twinkle but it is producing 4 spikes so as long as it has a good root mass then it can take that much feed, if it has not got a good root mass then I would however focus on the roots before the flowers. WE really need to see a picture to give proper advice as I could be advising you to feed it heavily but if the roots can't handle that then that would not be the right thing to do so please post a picture.

Added the images in the post
 

Hello shadeflower. I have added the images. Would you please care to take a look? I am feeding around 120 ppm every week and then again seaweed extract at 70 ppm every alternate watering ( my tap water is at 65 ppm). They are in bark and sphagnum moss mix. Thank you for coming to my aid so soon.

I can't see the photos well enough to tell.