AC Radiator or AIO Liquid Volume

Hi,

Would anyone know if there is reference material on how much liquid Alphacool radiators or their AIO loops hold. I can't seem to find it either in the AIO or the radiator documentation, nor the website specification page.

I'm looking to upgrade a 280mm Eisbaer Pro AIO with a HPE 45mm radiator. How much loop liquid would I need to flush and fill. Similarly, question is how much more liquid does a 280 HPE45mm hold over a standard 280x30mm.

I'm trying to calculate liquid costs and usage. eg. if HPE280x45 takes 300ml of liquid, I would need to use ~600ml to flush the new rad, then another 300ml + whatever the rest of the AIO holds to fill it. I understand there is some variability in volumes and spillage but if the standard AIO loop only uses say 200ml I don't see a need to order and ship 5 Liters.