"Marvin Hlavac groups: rec.aquaria.freshwater.plants" [email protected]
(A response on this NG told me it should be 50/50
Fluorite/gravel, which I guess I'll stick too.)
100% Fluorite is even better, but of course more expensive.
I have a 20w Tunze substrate heater.
I don't know about that particular one but I have heard a lot of people
their substrate heaters didn't last very long. Mine lasted only a few
I suspect substrate heaters are of no real benefit to a planted aquarium
where the whole bottom is covered with plant routes anyway.
Substrate heaters are supposed to be of long term benefit. They won't make
your plants grow faster, better, or nicer. But they will allow you to grow
them for many many years without getting a stale substrate.