Care of a Madagascar Lace?

Howdy,
I bought some bulb plants for the my 55 heavily
planted tank and one of them seems to be a
Aponogeton madagascarensis, which I guess is
what I know as a Madagascar lace since the leaves
sure look like lace to me. g

The plant seems to be doing very well, having
8+ stems all with 4+ inch long leaves. Only problem
I can see is that the plant has seemed to create extra
long stems to get the leaves up closer to the light and
they're now floating on the surface.

Is it normal for this plant to have long stems with leaves
up near the surface or is it a problem with the light level
or something else in my tank.

Water quality is 0 ammo, 0 nitrite 7.9ph, Kh12, Gh19
and nitrates vary around 15ppm.

Filtration is done by an Eheim 2026 and only 14 small fish
in it for now. Substrate is the new Carib Sea Eco complete
stuff I love it! and lighting is (2) 18" Spectra Max 6500K
15w T-8's

Any hints, comments or corrections are appreciated!

--
Later, Mike S.

There is no substitute for genuine lack of preparation. (: