The Cradle Ark is exposed to a variation in temperatures with the typical winter lows starting to be felt around this time of the year. The method of heating or trying to maintain a reasonable temperature, for either the aquaponics or for aquaculture, thus needs to be considered. The initial thinking was to combine a plastic tunnel with a low end solar heating method and a rocket stove design. However, a really interesting alternative exists in using a “Paine mound” or large compost heap to act as a heat supply , using a “thermo-siphon”, to circulate the water. All three need some experimentation , to see suitability at the Cradle Ark. The “Paine mound” overcomes the potential allure and possible removal of the solar heating system and is also not as reliant on labour post set up. The beauty would be that compost would be required for any traditional soil based planting anyway. It would also help keep the property in trim. The next question arising , is could the exotic cactus, dotted all over the Cradle Ark, be composted? The spines are a worry (maybe it will become a real pain mound?)but it would also remove the problem of the cactus and make use of the available material? The cactus self propogation would mean that the plant would have to be chopped up into small pieces. Could some reeds from the river be used in the paine mound? this would provide additional material and clean up the river a bit?