New baby plant, leaves turning yellow to brown
 

I inherited a purple orchid in quite bad shape and the main plant died but I noticed at the top some new leaves starting a new plant with ariel roots. I started to give this a daily spray of water and it shot several new leaves out but then suddenly started to turn yellow to brown. What am I doing wrong please?
Thank you
Ellwood

My speculation based upon no info other than the photo:

The roots of the original plant have suffocated in that soppy moss. The reserves in it are depleted, so it is no longer capable of supporting the offset (commonly called a "keiki" - Hawaiian for "baby"). You are not providing sufficient water through the keiki's roots.

Personally, I'd remove the keiki from the plant and pot it up by itself, in a medium better suited for your growing conditions. I'll also suggest the plant will need to be kept warm.

It looks like it might be a Dendrobium. Now that it is growing would be a good time to repot.

I can't tell how big that is, but use a pot only a couple of centimeters wider than the current spread of the roots growing from the new plantlet. Use a sharp blade to cut the aerial growth off the old part of the plant. For medium you could use fine to medium sized orchid bark, or the clay LECA balls sold at hydroponics shops. Whatever you use, there should be air spaces at the roots.

Water regularly after repotting so the roots become nearly dry between waterings. The frequency will depend on your temperatures. This kind of plant needs as much light as you can give it in England.

After it grows larger, post a photo, and we may have a better idea of the kind of Dendrobium. Care varies a little among the types.