Old bark mix

[Jasonmc89]

Hello everyone!

I have a Cat. walkeriana that I've had for years and has NEVER flowered! It is quite big, about 12-15 bulbs, nice and healthy roots, puts out new growths all the time, but no blooms..

I don't think it's a light issue as its unshaded in a south facing window and the leaves get little purple spots on them which I've read is an indication that it's receiving a good amount of light. I have had great success with oncidiums in the same location.

I also have it on a day/night thermostat so I don't think it's anything to do with the diurnal range. It's usually about 15 degrees C at night and 25-30 in the day.
The only thing I can think it that the potting media (bark chips) is breaking down and producing a lot of nitrogen which is suppressing blooming and just causing he plant to keep putting out new growths. Does this happen?

I haven't repottednit in about 2 or 3 years, just because it seemed to be fine.. But now I'm thinking otherwise.

Any advice would be greatly appreciated!

Thanks.