http://edis.ifas.ufl.edu/EH242 9fLORIDA $70 hot water batch heater) http://www.ata.org.au/articles/63shw.htm (Aussie batch heater) http://www.zapotecenergy.com/swhguide.htm (Haiti batch heater) http://www.motherearthnews.com/arc/2240/ (M.E.N plans, material list) http://sleekfreak.ath.cx:81/3wdev/VITAHTML/SUBLEV/EN1/ SOLRWTRH.HTM s