• Title of the invention: Instant reverse-flush aquarium and fish-pond filter.

• Field of invention: Relates to self cleaning aquarium and/or fish-pond filter systems.

• Background of the invention:

Almost all other aquarium and/or pond filters on the market today are in fact mini sewage plants. They have to biologically decompose the debris they capture in their substrate, and when this process has reached saturation they all still have to be cleaned by removing the filter or it's substrate, with much effort, stress and time involved for their user and sometimes even requiring the temporary removal of the live-stock, rocks, gravel and plants from the aquarium or fish-pond.

A minority of these other filters have separate mechanical filter parts that can be removed without too much trouble for partial cleaning to slightly reduce the load on the bacteria of the biological filter. Other filters also have removable chemical components or parts to neutralize toxins that can not be removed by the biological filter or are produced by it, and all this shows how inefficient traditional aquarium and/or fish-pond filters are, despite almost a century of research and development.

Our previous Australian patent 747968 and U.S. patent 6,234,113 B1 had already tried to solve the problem of removing the debris captured in the filter by elevating the substrate and flushing the debris collected underneath it while the fish were waiting in a separate "rock-pool" compartment. This system worked reasonably well but was commercially not viable, and only a small numbers of aquariums were ever produced with this system, which had to be built into the tank during it's construction.

However the new reverse-flush filter system which is derived from this first idea, has been developed over a period of 8 years to be self-contained, cheap to manufacture, easy to add to any existing aquarium or fish-pond of any shape or size, and still with it's main purpose being able to easily and regularly evacuate the solid detritus from the filter substrate instead of leaving these detritus to decompose on or in the filter substrate to be digested by the bacteria living on this substrate which are making up the so called "biological filter".

• Statement or Summary of the invention:

This is a self contained instant reverse flush aquarium and/or fish-pond filter system of which the main purpose is to be able to evacuate from this filter the solid debris captured by the mechanical function of the filter in a way that is very fast, very easy, with very little water wastage, and all this to reduce as much and as often as possible the source of the tank-water pollution and therefore also the load on the biological and chemical functions of this filter.

For this the substrate used in the conical filter-body compartment must always be smooth spherical heavy marbles preferably of not less than 8mm diameter and not more than 18mm in diameter (depending on the model and size of the filter), so that the detritus carried into the filter by the water-flow resulting from an air-lift or water-pump (power-head) action and passing through this marbles-like substrate contained in the filter body are able to settle-out by gravity separation in the spaces between the spherical marbles-like filter substrate while the clean water returns back to the aquarium or other vessel containing the aquatic life.

(•) This 8-18mm heavy spherical marbles-like filter substrate would never been used before in aquarium or fish-pond filters because it's surface area would be recognized by so called "experts" as being very insufficient for the "biological filter", but our own extensive and comprehensive experience has shown that this factor is practically irrelevant in the case of aquariums or fishponds usually relatively low live fish-stock densities and is the result of an ill-conceived practice promoted by the aquarium Industry out of pure commercial self interest, to the detriment of the interests of all aquarium hobbyists and aquarists.

The confirmation of this is clearly proven by the commonly called Berlin method which is the latest and most used method for indoor reef-aquariums, despite the fact that it does not have any "add-on" filter associated to it, so contradicting and negating all previously advanced ideas by the aquarium Industry promoting maximum add-on filter substrate surface area. Besides that, our aim is to remove the solid debris causing the pollution which might require the large biological filter substrate surface, as we believe that it is much better to avoid the cause of a problem rather than just treat the negative effects resulting from the problem. (••)

The filter body containing this spherical marbles-like filter substrate has to be of a special conical shape to allow the debris to settle-out in the spaces between the marbles-like substrate and accumulate at the bottom of this conical filter body so that they can be removed via a horizontal draining system directly connected to a vertical or horizontal extractor pipe (with or without valve) which may be temporarily connected to a flexible hose for siphoning and/or flushing operations.

To evacuate the accumulated solid debris, in some reverse flush filter models this flexible hose is pushed on to the above water-level end of the vertical extractor stand-pipe and the accumulated debris are flushed out using suction from the siphoning flexible hose aided by the inherent gravity pressure of the water left in the aquarium.

With other reverse flush models, one need only to open for a few seconds the valve of the horizontal extractor pipe connected to the drain system and the pump pressure in the filter will flush out the debris trapped near the drain, in the empty spaces between the marbles-like filter substrate.

For all reverse-flush filter models this procedure takes between 3 and 20 seconds and will use only about 1 to 3 liters of water per flush, depending on the size and model of the filter in use. Nothing has to be touched in the aquarium or fish-pond and the fish are not disturbed at all by the procedure which is also completely painless for the hobbyist.

This often and regular removal of the aquarium solid detritus is extremely beneficial to the purity of the tank or pond water and the health of the fish, it will drastically reduce the work-load on the biological filter and also reduce the production of Nitrates, Phosphates and other harmful noxious chemical or organic components. All this will greatly minimize other aquarium maintenance which is another source of stress for the fish live-stock and for the hobbyist

Presently only large aquaculture Bubble Bead filters are, by using small floating beads combined with an air-bubble burst technique, able to do something slightly similar to our filter system and are achieving the fast and easy evacuation of most solid detritus captured and accumulated inside their floating beads filter substrate. i

But by using relatively large and heavy marbles, our instant reverse-flush filter system is able to do this in a very different, much simpler and more economic way and for a much bigger size range and variety of aquatic vessels, plus our "Canister" and "Hang-on" reverse-flush models are the first aquarium/pond filters in the world having the possibility of 4 filter stages: mechanical, biological, chemical, and instant extraction of the captured solid debris.

Brief description of the drawings

Fig 1 : is a side view of the system according to an embodiment of the invention called

"Vertical Action" filter driven by an air-curtain air-lift. Fig 2: is a perspective view of the system in Fig 1. Fig 3: is showing the adaptation of the instant reverse flush system in an embodiment of a new modified commonly called "Canister" filter. Fig 4: is showing the adaptation of the instant reverse flush system in an embodiment of a new modified commonly called "Hang-on" (external or internal) filter. Fig 5: is showing the adaptation of the instant reverse flush system in an embodiment of a so called "Genie-in-a-Bottle" filter for fish-bowls or small fish-tanks.

Detailed description: AH Figures:

TW = tank wall TB = tank bottom AL = air-lift AC = air-curtain FB = filter body FG = filter grill MS = marbles substrate MS&SD = marbles substrate and solid debris W&D = water and debris CW = clean water ED = extractor drain EP = extractor pipe WP = water-pump S = Sand FH = flexible hose V = valve CD = current deflector SCV = siphon cut-out valve

The water-flow in the filter-body (FB) containing the marbles-like substrate (MS) is driven by an air-curtain (AC) creating an air-lift (AL) or by a water-pump (WP) also called power-head. With this flow the mixture of water and debris (W&D) enters the filter-body via a grill (FG) or pipe and once inside the solid debris are separated from the water by gravity, allowing the clean water (CW) to return to the tank and the solid debris to settle in the spaces between the marbles-like substrate (MS&SD) close to the extractor drain (ED).

Depending on the model of filter, to remove the debris a flexible hose (FH) is connected temporarily to the vertical extractor pipe's end (EP in fig 1-2-4-5) which must always remain above the water-level of the tank having the filter, or a valve (V) on the horizontal extractor pipe (EP in fig 3) is turned open and siphon suction plus gravity or pump pressure is used to reverse the water-flow inside the filter-body and flush out the debris in a short burst of tank water, hereby eliminating the source of most of the pollution potentially affecting the aquarium or fish-pond fitted with this reverse-flush filter system. For greater efficiency, fine sand (S) is used on the bottom of the tanks instead of gravel, to avoid the debris getting trapped there in; this forces the debris to stay afloat and to end-up inside the filter-body, later to be removed by the reverse flushing of the filter-body.