Question on heater-driven UGF plate

Hallo -

I understand some folks have had success obtaining substrate circulation
using a UGF plate with small heaters in the uplift tubes.  Talking about this
with my husband this morning, he wondered how you balance the need for
heating the tank with use of these very small heaters - do you still keep a
larger heater going?  How far above/below the little ones do you set its
thermostat in order to both keep the tank at temperature AND allow the little
ones to do their substrate work?

The need for a 125 is creeping up on us, and I want to be good & ready this
time!  Those pesky Siamese algae eaters are growing...

Anne Hull Seales
Santa Cruz CA