I had those ponds in the Limpopo province Tc..... where worst case scenarios fell to minimums of 12 deg C (mid winter).... but averaged around 33 in summer... (up to 41)...... I moved to Kimberley about 8 months ago... where we do go into the minuses (in winter) and I have heat the ponds with 400W heaters in each....(about 2,000 +l each... 5 of them)..... In summer I can switch off again....averaging around 30....... (not nearly what you fetch in Arizona though).....tcamos said:Perfect examples. Ludwig, how hot does it get there?