Petshrimp.com Discussion Forum

Ok, I see what you mean. Thanks for the information

Hi Mattias

The design of the HMF, large filter volume and very small water thorughput,

a little correction: not the volume but the surface is responsible for the efficiency(?)...

By the way - only the first 2-3 cm (1.5 inch?) are populated by nitrite reducing bacteria. Deeper inside the mat anaerobe bacteria will settle which might reduce nitrate if there is a carbon source (e.g. CO2).

Motor pumps just make sense in large filter with high flow and big surface...

Das Dee wrote:Hi Mattias

The design of the HMF, large filter volume and very small water thorughput,

a little correction: not the volume but the surface is responsible for the efficiency(?)...

By the way - only the first 2-3 cm (1.5 inch?) are populated by nitrite reducing bacteria.

It's actually the surface area available to bacteria the determines how much space is available to colonize. But it's important to remember that this is all the area inside the filter. Ever place that gets into contact with water. Most filter media have an area/volume value of how much colonizeble surface there is in that media. When making comparisons between sponge and HMF it's simple just to count the volume since the media is usually similar. That is, medium to fine sponge. Also the bacteria are oxidizing ammonia into nitrite and nitrite into nitrate, the reverse of reducing.

Das Dee wrote:Deeper inside the mat anaerobe bacteria will settle which might reduce nitrate if there is a carbon source (e.g. CO2).

Nitrate reducing bacteria need an organic carbon source so CO2 or carbonates is no good for them. Sugar and ethanol are sometimes used in waste treatment and in marine aquariums to facilitate the growth of anaerobe bacteria.

Das Dee wrote:Motor pumps just make sense in large filter with high flow and big surface...

There are small centrifugal pumps with a flow in the 100L/h range. These can be constricted to output even less and thus do well in small tanks with an HMF.
cheers
Mattias

Great pictures at that link.

Inexpensive, easy to make, quiet, efficient, hides the heater and it is not unattractive if you use a dark mat.

Thank you very much for the post.

I will be trying this filter design with my next set up.

PS. Do you... and if you do... How often to you rinse the mat?


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-Wingnut

I've been using the HMF filter for a while on some of my tanks. I like it.. Very low maintenance. I've tried two variations. One using it in a 20gal sump for my 180gal plant tank. The other attached to the plate for a UGF in a fry tank. Both worked very well. HMFs can clog, it's just that it takes much longer than say a HOB filter because you have so much more surface area. Never had a problem with debris floating around in a tank with one, anything that is too massive to get pulled into the filter settles to the bottom of the tank. I highly recommend this type of filter for any tank with tiny critters that might get sucked into a normal power filter. Much better than panty hose over the intake of a power filter in my opinion. I also like air powered sponge filters for small tanks with tiny critters, However they do make noise, and the bubles can spash tiny drops of water up onto the tank lid. The downside of a mattenfilter with a pump is that in a small tank it can create too much turbulence on the return output even if it has a gentile intake, and you end up blowing your tiny critters across the tank. With a larger tank they can get away from the area of turbulence. So just remember with the little tanks you also need to diffuse the output somehow too.

A small powerhead with the outflow angled toward the surface would probably be best. It would provide more surface agitation/gas exchange, and minimize the turbulence around the bottom of the tank.

Hi,

wingnut247 wrote:PS. Do you... and if you do... How often to you rinse the mat?

we had to rinse 3 mat after moving. These filter run from 2 to 4 years without maintaining. The mat were clogged by duff(?) which was disperse while refilling the tank.

Normally the duff(?) will not disperse because of the low flow inside the tank. Calculate 2 times tank volume for your power head and a appropriate mat size.

These filter run from 2 to 4 years without maintaining.

That is very low maintenance Could you also let us know if there are any details you consider important in building the filter that is not covered above. The pictures are great in the site link but I just wanted to know if there were any tips you wanted to give

Thanks.

Hi,

there is nothing special to know about this kind of filter...
Just calculate the correct size of the mat...

If I would kid you, I would ask you to calculate the mat size to a throughput of 7.5 cm/min . But I guess it's better to give you this link - unfortunately in german:
http://www.deters-ing.de/Berechnungen/B ... m#gebMatte

Die gebogene Matte - The bend mat

Höhe Aqua (cm) - height of tank in cm!
Pumpe (ltr/h) - pump liter per hour
v (cm/Min.) - throughput - just leave it at 7.5 cm/min
The result (e) will be the distance for the glass stripes from the corner

Ich würde den Mindestabstand immer mit ca. 3x Mattenstärke ansetzen und ggfs. die Pumpenleistung erhöhen, damit die Strömungsgeschwindigkeit nicht zu stark abnimmt.

"I would set the min. distance to 3 times of mat thickness and as necessary increase the throughput of the pump, so the flow speed will not decrease to much"

There are some tips for the HMF like a bend piece of plastic glass at the bottom, so the sand/gravel can not slip in the filter chamber when removing the mat.
Others are sewing (!!) some java moss or other kind of plants on it.
Some use cable channel instead of glass stripes.

Thats all - no, wait: Make sure the silicone is usable for fish tanks!!!

A last hint - this manual is for "dry" tanks. If you set up a new tank you can use it. Otherwise you have to dry your tank...

Another thing: Some of our shrimp like graze(?) the filter

And the last (I already wrote) look for your right pore size as the shrimp childs are able to walk though a to raw mat...

Br.,
Dirk (<- got this in my signature but it was not shown to me jet )

Thanks for the translations and great tips This will help anyone who wants to build the filter.

Das Dee wrote:The mat were clogged by duff(?) which was disperse while refilling the tank.

You can say mulm in English, too. Same word, same spelling as in German...but with the English pronunciation of course. Other more general words are detritus and debris.

Br.,
Dirk (<- got this in my signature but it was not shown to me jet )

I disabled signatures several months ago as some people were misusing them for their own (commercial or similar) purposes by posting links in their signatures. Plus, some people put huge pictures in their signatures which would take up half of the computer screen. I might introduce signatures in the future again, but only if I can disable links and HTML in the signature part.

Hi Mustafa,

You can say mulm in English, too.

I used online translation which gives only one possibility...

Br.,
Dirk

Hi Wingnut,

and it is not unattractive if you use a dark mat.

don't worry - the mat itself becomes dark by and by...
This bright blue disappears - belief me

Br.,
Dirk