Had all 3 x 300w heaters running now from 6.30pm.Its holding the same temp as main pond at 63f, I will check again in the night, but it is getting cold and windy outside so we will see.
All things being equal my kohaku will now go in tomorrow night.
My tank is running at around 23.4ish and stays there and the heaters are not even coming on at the moment as it is so well insulated.I use two aquarium heater but once its up at the temp i unplug one and then it stays stable.
