Impeller assembly for use in an aquarium filter pump and methods

1. A method of pumping water for an aquarium filter, the method comprising:

(a) rotating an impeller in an aquarium to draw water into the filter;

(b) wherein the step of rotating the impeller includes rotating blades, each blade including:

(i) opposite blade faces having a plurality of edges; and

(ii) a depression in each of the blade faces; the depression increasing in depth within the respective blade face as the depression extends to one of the edges; a maximum depression depth being a thinnest portion of the blade faces;

(iii) a periphery with a shape of two opposite parallel sections that round to a vertex portion having a sharp point;

and wherein the depressions aid in pushing the water.

2. The method of claim 1 wherein:

(a) the impeller includes a shaft having a longitudinal axis;

(b) the blades extend radially from the shaft and along a plane containing the longitudinal axis of the shaft.

3. The method of claim 2 wherein the step of rotating blades includes each blade having a plurality of straight edges.

4. The method of claim 3 wherein the step of rotating blades includes each blade vertex portion being adjacent the shaft, and with a free edge remote from the shaft being a deepest portion of the depression.

5. The method of claim 3 wherein the step of rotating blades includes each blade having the vertex portion adjacent a first edge, and an opposite second edge being a deepest portion of the depression.

6. The method of claim 3 wherein the step of rotating blades includes each blade having the depression increasing in depth as the depression extends from adjacent the shaft to a free edge.

7. An impeller for use in an aquarium filter pump; the impeller comprising:

(a) a shaft with a longitudinal axis; and

(b) a plurality of impeller blades radially extending from the shaft;

(i) each of the blades including opposite blade faces having a plurality of edges;

(ii) each of the blades being along a plane containing the plurality of edges and also containing the longitudinal axis of the shaft;

(ii) each of the blades having a depression in each of the blade faces; the depression increasing in depth within the respective blade face as the depression extends to one of the edges;

(iv) each of the blades having a periphery with a shape of two opposite parallel sections that round to a vertex portion having a sharp point;

wherein a maximum depression depth being a thinnest portion of the blade faces.

8. The impeller of claim 7 wherein the plurality of edges are straight edges.

9. The impeller of claim 7 wherein the vertex portion is adjacent the shaft.

10. The impeller of claim 8 wherein the vertex portion is adjacent a first edge, and an opposite second edge is a deepest portion of the depression.

11. The impeller of claim 8 wherein the depression increases in depth as the depression extends from adjacent the shaft to a free edge remote from the shaft.

12. The impeller of claim 8 wherein there are no more than 4 blades.

13. An impeller assembly for use in an aquarium filter pump; the impeller assembly comprising:

(a) a shaft with a longitudinal axis;

(b) a rotor mounted on the shaft; and

(c) an impeller mounted on the shaft; the impeller having at least 3 blades radially extending from the shaft; each of the impeller blades including:

(i) opposite blade faces;

(ii) a free edge remote from the shaft;

(iii) first and second opposite edges extending from the shaft to the free edge; the blade faces being bordered by the first and second edges and the free edge;

(iv) a depression in each of the blade faces; the depression being at maximum depth within the respective blade face at one of the edges;

(v) a periphery with a shape of two opposite parallel sections that round to a vertex portion having a sharp point;

wherein the maximum depth being a thinnest portion of the blade faces.

14. The impeller assembly of claim 13 wherein the depression increases in depth as the depression extends from adjacent the shaft to the free edge.

15. The impeller assembly of claim 13 wherein there are no more than 4 blades.