Yeah, I just wanted to see how warm the water would get:- Was gonna fill 2 doz of 'em & then pump/pour into a little blow-up pool in the garden!! This was in the height of summer tho'!
I have 90ltr water tank on the roof ... up front .. used a roof box to house the tank .. let gravity do the work ... use a fixed connector ie hose lock ..let the tap pressure do the work .to fill the tank ...water gets quite warm on a sunny day
this is why a coil of black pipe works better; the water doesn't slosh about and the heat absorbing area is massive compared to the diameter of the pipe. also on a hot day even once the heated water has been pumped out,the cold going in has warmed by the time it's travelled 50 metres ! and the main water supply is on or under the floor