I'm running* my ATL-1 with a non-Jobo 5 l heater connected via a normal
thermostatic shower valve. I was lucky and got the heater on ebay for a
song. Normally, they are quite expensive even if you don't buy them from
Jobo because this application requires one of the somewhat rare
pressurized heaters as opposed to the more current non-pressurized
variety. You'll also need an additional fixture that controls the
pressure rise when the water heats up.

Don't try this with a non-pressurized heater. It will burst.

My set-up works fine with C-41. Don't know if the precision would be
good enough for E-6. But given that the water flows through yet another
heat exchanger inside the ATL before reaching the film in the tank, this
should be OK as well.

Ralf

*) Well, used to, until the electronics went up in smoke. No more spares
from Jobo. Anyone with a spare set of PC boards for an ATL-1? :-(