Is a 240 L/s demand unobtainable?

Hi all, very new to this software so please bear with me,

Essentially I plan on modelling a hydrostatic testing facility to pump two storage bottles of approximately 1,000,000 litres each, with a 240 L/s pump. Every time I try to introduce a pump to try to get this sort of flow rate, the pressure on the nodes is extremely high, or the pump doesn’t work and then the head loss is extremely low (due to high demand from the node). I was wondering if the end point should be modelled as a node with a certain demand (currently have it set as this), or a tank of 1,000,000 litre capacity.

Please let me know if you have any ideas, or if I’m not making any sense at all.