I know this may sound impossible, but perhaps there is a way?

Basically I came to aquarium plant interest via keeping fish and as someone
with little knowledge of same at first listened with avid interest to
anything the store staff told me about aquaria.

Although over the years my fish thrived and were content, i was never happy
with my plants, i seemed to be always replacing them.
It was only after reading up on the subject did i realize i even needed a
proper substrate!
When I had purchased my tank i was told i needed about 2 inches of sand or
gravel, it seemed odd to me at the time as plants wouldn't have much 'grip'
but what did i know?

Currently I have a thriving tank (44 gallons) and although I have
compensated for that bad advice by using various methods (co2 generator,
root tabs etc) I would prefer to do it properly.
However, I don't have the money for a second setup and was wondering is
there ANY way I can introduce a 3 tier substrate into a existing tank?

I had one idea; and that was to build up an area at a time, not ideal no,
but at least my poor plants would finally get a proper chance at both
surviving and flourishing.
The idea would be to remove the plants, rocks and bogwood from say an eighth
of the tank then add the three layers that way, wait a month for things to
settle then move on to the next section.

The plan was to lay down potting vermiculite, then soil and finally the sand
(again thanks to Jim Kellys superb article).

Thoughts?
Is it possible or can you think of another way to give my plants SOME better
chance at survival in an existing tank?

Many thanks in advance

Steve Page