Filtration system for aquariums

A filtration system for an aquarium having water and fish. A container is mounted in juxtaposition to the aquarium and a porous filter is disposed in the container. The top of the filter is connected to the bottom of a pot in which is growing a terrestrial plant in soil. A pump circulates water from the aquarium into the container and through the filter. The filter removes solid and dissolved pollutants from the water and roots of the plant grow into the filter, utilizing the pollutants retained in the filter.

CROSS REFERENCE TO RELATED APPLICATIONS (NOT APPLICABLE.) 
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT (Not 
applicable.) 
REFERENCE TO A MICROFICHE APPENDIX SPECIFYING THE TOTAL NUMBER OF 
MICROFICHE AND TOTAL NUMBER OF FRAMES (Not applicable.) 
BACKGROUND OF THE INVENTION 
The present invention relates to a filtration system for aquariums and more 
particularly to a filtration system in which the roots of a terrestrial 
plant grow into the filtration means and utilize the waste products from 
the aquarium carried by the water. 
Filtration is an important consideration in an aquarium which serves the 
following functions: 
To remove unwanted gross solid particulate matter such as uneaten food and 
feces (mulm) from the water so as to keep it clear. 
To remove unwanted coloring matter, which gradually accumulates in the 
water, turning it yellow and then brown if it is not frequently changed. 
Occasionally to remove algal or bacterial "blooms", which cloud the water 
and make it opaque, green, or milky in appearance. Algae utilize oxygen 
and severe algal contamination depletes the supply of oxygen and can 
result in oxygen starvation of the fish. In addition, some algae produce 
toxins which are poisonous to the fish. 
To remove invisible, colorless dissolved matter such as ammonia and 
nitrites that are poisonous to the fish in all but minute amounts. 
An ordinary coarse filter material such as synthetic filter floss or filter 
pads of various types only copes with the first item above when it is 
first set up or if the filter is frequently cleaned out, but as time goes 
on an old filter bed may start performing some of the other functions as 
well, particularly removal of dissolved matter. This is because bacteria 
grow in it that convert unwanted products of fish life, such as those 
listed, to harmless ones--particularly nitrates--which are utilized by the 
plants. 
The main toxic material produced by the breakdown of excreta, uneaten food, 
etc., is ammonia. This is converted to nitrites by bacteria such as 
Nitrosomonas, then by further bacterial action, involving Nitrobacter, the 
nitrites are converted to nitrates. Both ammonia and nitrites are harmful 
to fish, even in minute amounts (200 to 300 parts per million), and can be 
monitored by suitable test kits. However, if bacteria growth is not 
present, the decomposition of uneaten food and mulm produces toxic 
substances which may kill the fish. 
Another popular filter material, activated carbon or charcoal, performs, in 
particular, removal of coloring matter and dissolved matter right from the 
start. Fine granulated so-called gas grade charcoal has an enormous 
adsorptive surface on which chemicals of all descriptions may be adsorbed, 
and on which bacteria may also grow. These bacteria may interfere with the 
charcoal's main function, although a balance often seems to be achieved, 
with quite old charcoal continuing to adsorb chemicals and grow bacteria. 
Eventually, it will clog up and have to be replaced, but it can take up to 
more than half its own weight of adsorbed materials with it. When in a 
semi-clogged condition, both filter wools and activated charcoal extract 
finer and finer materials and may assist in removal of algae. Most of the 
desirable functions of a simple filter will be performed if it is provided 
with a bed of fine filter floss and activated charcoal. The charcoal is 
usually placed between layers of floss, so that it cannot escape into the 
aquarium. 
The simplest filter is a box filter which is disposed inside the aquarium 
and is generally placed in a back corner where it is less visible. The box 
is usually a transparent plastic container filled with a combination of 
filter wool and charcoal (sometimes with gravel). A layer of charcoal is 
sandwiched between the filter wool, with gravel on the bottom to weigh 
down the container. 
Other filters may hang inside the top of the tank, or outside the top of 
the tank, and are then known as "inside" or "outside filters. An airlift 
conveys water into the filter using a simple injection of air into a 
plastic tube. In an inside filter, the airlift curves over at the top, the 
air-water mixture flows into the filter and the water passes down through 
the filter bed and escapes back into the tank via perforations at the base 
of the filter. In an outside filter the water is drawn into a tube by an 
airlift in the tank and so returns to the tank, while one or more siphon 
tubes convey water from the tank to the filter, where it passes through 
the filter bed (or beds) and back into the tank. It is preferred that a 
pump be used with an outside filter to draw water up from the tank, pass 
the water through the filter and return the water to the tank. 
U.S. Pat. No. 4,169,050 discloses a wastewater treatment for a pond which 
has floating aquatic plants, submerged bio-web substrates and aeration by 
submerged perforated air diffusers and a floating aerator. 
A terrarium/aquarium combination is disclosed in U.S. Pat. No. 4,754,571. 
The plants in the terrarium are separated from the aquarium by a vertical 
partition. The combination provides an apparatus for humidifying indoor 
air. Included are filter plates beneath the terrarium substrate and in the 
aquarium. 
A fish farm and hydroponic greenhouse are disclosed in U.S. Pat. No. 
5,046,451. The fish tank is equipped with a submerged biofilter with 
vertical channels and underlying air lines. Air bubbles rise in the 
channels to agitate and aerate the water. 
U.S. Pat. No. 5,121,708 discloses a hydro culture crop production system 
for raising land and aquatic plant and animal crops. 
BRIEF SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a filtration system for 
an aquarium which removes the waste products from the fish, excess food 
for the fish and algae to maintain the aquarium in a clean condition. 
It is a further object of the invention to provide a filtration system for 
an aquarium which enhances the natural beauty of the aquarium. 
In accordance with the teachings of the present invention, there is 
disclosed a filtration system for an aquarium. The aquarium has water and 
fish therein and a pump means to recirculate the water. The system further 
includes a container having an open top mounted in juxtaposition to the 
aquarium. The pump means is in fluid communication with the container 
wherein the water is circulated between the container and the aquarium. 
Filtration means are contained in a porous cartridge which has a top. The 
cartridge is disposed in the container such that circulating water 
carrying waste products from the aquarium passes through the porous 
cartridge. A pot having a bottom with an opening therein is mounted in the 
open top of the container. The opening in the bottom of the container is 
in communication with the top of the porous cartridge. The pot further 
contains soil and a plant having roots growing therein. The roots of the 
plant grow into the cartridge and utilize the waste products carried by 
the water recirculated from the aquarium, such that the aquarium is 
maintained in a clean and substantially algae-free condition and the plant 
grows in the pot. 
A method of filtering water in an aquarium is also disclosed. 
These and other objects of the present invention will become apparent from 
a reading of the following specification, taken in conjunction with the 
enclosed drawings.

DESCRIPTION 
Referring now to FIGS. 1-4, an aquarium 10 has fish F and water W therein. 
The fish F produces solid waste products which contain some water soluble 
nitrogenous materials. When the fish are fed, there is usually an excess 
of fish food which remains in the water. These substances are conducive 
the growth of algae within the water. In order to remove these substances, 
to maintain the aquarium in a clean condition and to improve the health of 
the fish, the aquarium is provided with a circulating pump and a filter. 
Most frequently, the filter consists of a bed of charcoal granules and a 
fibrous material such as glass or nylon wool. The fibrous material removes 
the majority of the solids which are circulated and the charcoal entraps 
additional solids. The charcoal further retains some of the dissolved 
material and traps gasses which are dissolved in the water W. The filter, 
in the prior art, is frequently disposed within the container with tubing 
connecting the filter to a pump which circulates the water in the aquarium 
into the filter. Alternately, in the prior art, the filter is disposed in 
a container attached to, or adjacent to the aquarium, and the water is 
circulated between the filter and the aquarium by the pump. 
In the present invention, a container 12 is mounted in juxtaposition to the 
aquarium 10 such that the water W in the aquarium 10 is in fluid 
communication with the container 12 and water W is contained in the 
container 12. A pump 14 circulates the water W between the aquarium 10 and 
the container 12. It is preferred that the container 12 is mounted at the 
top of the aquarium 10 so that water W overflows from the container 12 
into the aquarium 10. However, it is not necessary for the container 12 to 
be disposed for overflow of the water W. It is necessary for water W to be 
exchanged between the container 12 and the aquarium so that unfiltered 
water can be introduced into the container 12, pass through a filter 16 
and return to the aquarium as cleaned, filtered water W. 
The filter 16 is a porous cartridge 18 with a filtration means 20 within 
the cartridge 18. The filtration means 20 is granular charcoal, filter 
plate, gravel, baked clay chips, glass beads, etc. The most efficient 
filtration means 20 is charcoal, and in particular granules of activated 
charcoal. Charcoal plate or other configuration of charcoal are also 
acceptable. The porous cartridge 18 may be a fibrous material through 
which the water W passes without restraint or a thin walled material 
having a plurality of openings therein through which the water W passes. 
The cartridge 18 must be able to retain the filtration means 20 inside the 
cartridge 18. 
The top of the cartridge 18 is connected to the bottom of a pot 22. The pot 
22 contains soil 24 in which is growing a terrestrial plant 26. The size 
and shape of the pot 22 is not critical, the only restriction being that 
the bottom of the pot 22 have an opening 28 which is in communication with 
the top of the cartridge 18 of the filter 16 and that the pot 22 be 
supported above the container 12. 
The roots 30 of the plant 26 grow through the soil 24 and out of the 
opening 28 into the cartridge 18 (FIG. 5). As the water W from the 
aquarium 10 is circulated from the aquarium 10 into the container 12, the 
water W passes through the porous cartridge 18 (as shown by the arrows A 
in FIGS. 3 and 4). The solid material such as waste from the fish F, 
excess fish food and algae are collected on the fibrous material of the 
cartridge 18 and in the filtration means 20 within the cartridge 18. The 
roots 30 of the plant 26 utilize the solid material and the dissolved 
nitrogenous material in the water W. In this manner, the plant 26 which is 
external of the aquarium 10, continuously removes the pollutants from the 
water W and the pollutants are not returned to the aquarium 10. The 
filtration means 20, especially charcoal, trap gasses that promote aerobic 
biological activity and support growth of the roots 30 of the plant 26. 
The plant 26 develops a growing extensive root 30 system with a very large 
increasing surface area to remove greater amounts of pollutants from the 
water W. As a result, growth of algae in the aquarium is significantly 
reduced and the concentration of dissolved nitrogenous materials is 
controlled. Thus, the fish F are not harmed by a build up of dissolved 
nitrogenous material and are not competing with the algae for oxygen. This 
promotes healthy fish F which thrive in a clean aquarium 10. 
In addition, the appearance of the aquarium 10 is enhanced by the presence 
of a growing terrestrial plant 26 next to the aquarium 10. The plant 26 is 
continuously supplied with water W. The water W is heated to the 
temperature of the aquarium 10 and root 30 growth is stimulated. The type 
of plant 26 is not critical and, flowering plants of various varieties may 
be used to enhance the appearance of the setting. 
The above described system and method of filtering the water W of an 
aquarium 10 is not limited to an aquarium but may be applied to larger 
bodies of water such as a pond or a fish farm, so long as an adequate 
filter (or filters) is provided with filtration means to remove the 
pollutants and there are sufficient plants to utilize the pollutants which 
are removed from the water. 
Obviously, many modifications may be made without departing from the basic 
spirit of the present invention. Accordingly, it will be appreciated by 
those skilled in the art that within the scope of the appended claims, the 
invention may be practiced other than has been specifically described 
herein.