Membrane diffusers are very popular. Check out Vertex and Matala brands too. Esshup sells the Vertex ones on his website. See his signature above. And, many people here like their Gast pumps.
With the 0523 and 3 diffusers, placement is not too critical since you are moving plenty of water. Esshup has been at this for some time now and his advice will have its advantages.
