Hey TJ - yes mate they do bring pretty reasonable tanks these days it seems. I've never had a problem with the quality of them so far. To order online is really easy go to Principal Grupo Zeta on the main page there about halfway down you'll see "pedidos en linea" http://www.grupozeta.com/pagina_internet/index.htm?html=formatos/pedidos.jsp just click there and fill in the simple form (no registering or nada required) click "enviar" and you're done. The price sounds about right as well - but I'm not 100% sure on that.
what we do to check our gas tanks for our annual smelt fry is slowly pour hot water down the side of the tank and feel for where the tank is cooler. the filled part of the tank will not warm up as fast as the empty part of the tank. of course this is annually, monthly would be a pia.
