On the topic of filters I believe it is best practise to have at a minimum some type of mesh screen filter to prevent large objects entering the pump and causing damage. These types of filters do not improve the water quality and consequently have little impact on the pumps performance.
EWB Australia acknowledges the traditional custodians of country throughout Australia and recognise their continuing connection to land, waters and community. We pay our respects to them, their cultures and their land; to Elders both past and present; and to emerging leaders. We recognise that the Aboriginal & Torres Strait Islander people never ceded sovereignty of what we call Australia.