I don't think you can do this with a single boiler unless the water in both ponds is linked up in some way. The problem is, you only have one thermostat so which pond do you measure without either over-heating or under-heating the other?
You will need two seperate circuits controlled from independant thermostats if the ponds are isolated from one another.
Alan
Posted on Dec 16, 2005, 3:44 PM from IP address 213.120.101.21