The old guy who offered me the plant believe it or not has a heavily planted tank (been going for 20+ years) with a sand substrate, doesn't have a filter doens't believe in them and does NO WATER CHANGES, just tops up the water as and when it is needed !!!!
Says that the plants filter the water and take out the nitrates etc, no problem with fish either.
As there is no water movement this could be the reason why this particular plant has not succeeded in his tank.