Crypts - substrate heating

While I have spent my annual air-time allowance in the last 2 months trying
to digest the information available about aquatic plants on the web - a *few*
questions have developed (I'll limit myself):

- Is it true that crypts do poorly with substrate heating? Almost everything
seems to point me in the direction of substrate heating but when I read that
George (& others) had crypts that did poorly, I was crushed.

- Why does it appear that Takashi Amano (Nature World Aquarium) can grow
all(?) with no laterite and no substrate heating (including crypts) for years
without a teardown?

Ron Lane
whirlabout at aol_com