used 20,000-liter stainless steel insulated tank, it is a vertical tank made entirely of stainless steel with 5cm thick rock wool insulation made later (unfortunately it was a bit damaged during dismantling). the label probably remained under the insulation but it should be twenty thousand liters and was used as a water reserve for system washing. dimensions: Ø200cm h730cm, int. Ø190cm h670cm