Fusarium Wilt
 

I just noticed this yesterday but today the whole bulb is purple. The leaves feel turgid and looks good. There is no roots though and managed to lived for about 4 weeks now without it. Is it dying?

https://lh5.googleusercontent.com/-n...221_184702.jpg

https://lh6.googleusercontent.com/-g...221_184705.jpg

Could be. But many cats and laelias have this coloration on the pbulb and even leaves.

I agree. It is a natural color of the plant.

Fusarium does not show up as purple like that.
It is more like black and the plant will look very dehydrated.
Your plant doesn't fit any.

I believe the root loss is due to too much watering and as a result, fungi come and take care of the dead mess (not a pathogenic but opportunistic one).

I think it can still survive but it would be a tough road.

I happen to catch this video on Youtube. Do you recommend this process to stimulate new roots??

AOF Cattleya bare root shipping process - YouTube

Yes, just by looking at their results and look at the beautifully grown vandas in the background.
He knows how to grow orchids! :)

I believe he is in the tropical zone.
You are in a warm area as well, but winter can get chilly even in Florida as I have spent a few winters in Florida, even further south than Tampa.

Keep them warm, bright, and high humidity and just give it time.

There are no roots at the moment, so it's best to have it stand on moist moss or something similar.

I would rinse the base of the plant with light dilution of Clorox or hydrogen peroxide to kill off all the molds and other stuff that might be present.
This will help give you the fresh clean start.

I liked the video. It shows how easy it is to divide/grow cattleyas and many other orchids. Yes he is in a very warm country and the warmth and humidity help the orchids grow fast. Notice that they don't even put media in the pots for a few weeks. It's not necessary to put media in the pot until roots begin to show. But you need to keep the plant hydrated all the time. The energy to grow is already in the old pbulbs. No media or food necessary until the new roots start to grow.

It has been very hot and humid here in Florida but the nights are cool. I have a heater with a fan and the bathroom is nice and muggy.