Ray
Member
This Ebay seller (http://stores.ebay.co.uk/International-Fish-Street) is offering Flow Eductors (http://stores.ebay.co.uk/Internatio...Z4QQdirZ1QQfsubZ12840653QQftidZ2QQlnsZ1QQtZkm):
The linked review (http://www.advancedaquarist.com/issues/sept2003/review.htm) says:
The linked review (http://www.advancedaquarist.com/issues/sept2003/review.htm) says:
As water enters the eductor, it flows into a narrow section that increases the velocity of the water. As the water continues, it exits the narrow nozzle into a section with a much larger cross section. This expansion creates a pressure gradient that draws water through the surrounding slots into the stream. The process of drawing water from outside the eductor effectively increases the apparent flow from the pump over what a simple return would provide.
Would this help with flow in a planted tank and is the outflow from an external filter "pressure rated"?To reach these kinds of efficiencies, the pump feeding the eductor needs to be pressure rated. It needs to be able to generate flow against the back pressure of the narrow nozzle.