How to build a Hamburg Mat Filter

[fishman2]

The Hamburg Mat Filter

The Hamburg Mat Filter, HMF for short, has been in use in the Hamburg area of Germany since the early 1960’s.
The Hamburg Mat Filter uses a single section of filter foam as the biological filter medium. In the first designs, these sections were installed on either side of the aquarium, side to side, bottom to top



The filter foam used is reticulated foam specifically made for filtration purposes and without any chemical additives. The density of foam used is usually 10, 20 or 30 PPI
(Pores per inch).


http://www.swisstropicals.com/
Filter Foam is available thru Swiss Tropicals or a local manufacturer in your area
The thickness of material is usually 3 or 5 centimeters thick.
These choices are influenced by the tank size and type of inhabitants. Fine foam is better suited for shrimp and fry rearing tanks, Course material (10 PPI) is more suitable for large fish. The thickness is



dependant on the size of the tank as the thinner foam will not be stable in a larger section.
Traditionally the foam is installed into a plastic channel which has been siliconed to the tank sides and bottom. I personally have found it to be accecptable to friction fit the foam into the tank end side to side, the foam remains in solid contact with the bottom by pushing the top below the plastic trim of the tank.
Many other configurations are possible, corner, semicircle and even hang on the back versions.
The required size of the filter mat can be determined using the following equation

V x T x A = Filter area

V= volume in litres
T= volume turn over per hour (2 is recommended)
A= approach speed in centimeters per minute (5-10 is recommended, I use 7.5)

You will find that the Mat Filter area will be correct for most standard size tank sides.

The calculation is necessary for other shapes and locations.

You may say that this is just another sponge filter, well, you are right and wrong!
The Hamburg Mat Filter has a very large filter area, far larger than any standard sponge filter, this allows for optimum dwell time of water in the filter medium to maximize the biological filtration activity. In addition to this a build up of beneficial bacteria will occur behind the Mat! Do not remove this bacterial build up.
Many hobbyists, including myself have found that once a Mat Filter is installed, cleaning is not required for very long periods of time (2-3 years or more).


Moving the water thru the mat can be achieved in one of 2 ways, the installation of a power head or an air lifter.

My personal preference is with an air lift ( I currently use a central air pump with an output of 80L/min to drive 32 tanks with a total volume of 1100 gallons), This makes the system very economical to operate.

The Air lifters are constructed as follows

• Parts list: pipe1” pipe,11/2” pipe, 2 - 32x4 – O rings, 3/16” rigid air pipe



Drill a series of 1mm holes around one end of the 1” pipe (2 or 3 rows)


Install one o ring above the rows of holes and another below it as follows




Drill a 3/16” hole into the 11/2” pipe section and install a short piece of 3/16th rigid pipe (friction fit)




Slide the 11/2” pipe over the 2 o rings, this creates the pressure chamber


Attach the 1” electrical PVC elbow and cut the exit side on a 60 degree angle



Now attach your air line and you are ready, The finished lifter should be about 1.5” above the bottom of the tank and the exhaust should be right on the waterline.

You can anticipate an output ratio of 1:2 Air: Water, this will be achieved at 90% capacity for the size of pipe you are using

The following is a list of other pipe sizes I have used

• 16mm pipe/ 20mm coupling/ 16x2.5 – O

• ¾” pipe/ 1” coupling/ 25x4 – O

This is the most efficient air lift design I have been able to find!

So try out a Hamburg Mat Filter on a tank, you will be pleased!

For further information I recommend the following web site (it’s in German, but translates well) http://www.deters-ing.de/


By: Udo Rohmann

photos to follow