I have been lucky enough to inherit an old (but in excellent condition) Berlin skimmer that is just about 500-550mm high. It says its a hang on type but want to use it in the sump incase of overflow hic-cups. The sticker says something like 25-25000 but is faded. I want to know what size/flow rate pump/powerhead I should use. My tank will be +-160 litres with sump of +-65 litres. Hope I've given enough info for a reply?