DIY internal filter

[Robert]

Hi,
yesterday I build a new internal filter. I was inspired by the "Hamburger Matten filter" which looks like this:

http://www.deters-ing.de/Filtertechnik/Geb-Kabelkanal.jpg
(the picture was taken from here: http://www.deters-ing.de/Filtertechnik/FilterBilder.htm

But I didn't want to use glue and things like this to attach the mat on one tank side or corner. So I build a round mat. The idea is not new but I found out about this after I finished my filter, so it was a new idea for me :p .

I use a piece of a fine 3cm thick sponge filter mat with the size of 23 x 46cm. I also used a small submersible pump, fishing line, a short piece to tubing and a stone. At first I rolled up the pump inside the mat before I cut the mat to its size. Then I sewed the sides of the mat together with the fishing line. When I finished, I got a long sponge tube with a pump inside. It looked like this:

http://www.shrimpnow.com/gallery/albums/userpics/10003/normal_DIYFilter2_02.jpg

That is the bottom of the tube. I inserted a stone to weigh down the mat because it should stand later on and to close the hole. This pictures shows the stone in the mat:

http://www.shrimpnow.com/gallery/albums/userpics/10003/normal_DIYFilter2_03.jpg

Then I cut a hole in the mat for the pump outlet. I connected a short piece of tubing and ready was my filter:

http://www.shrimpnow.com/gallery/albums/userpics/10003/normal_DIYFilter2_01.jpg

The whole filter looks like this:

http://www.shrimpnow.com/gallery/albums/userpics/10003/normal_DIYFilter2_04.jpg

It's not the prettiest filter I ever saw but it does not matter because I'll use in my breeding tank. The filter stands upright in the tank in one corner and now I test it. The principle is the same like the "Hamburger Matten filter", so it should run for a pretty long time before I have to clean it. Another reason for building it was it's price. I got the pump for 5€, which is quite cheap and the filter mat costs also only some Euro, so this filter is much cheaper than commercial ones and the filter volume is several times bigger than normal internal filters.

best regards

Robert

[stcyrwm]

Robert,
How is the filter setup working? I've been looking for a simple design like this and would like to give it a try.

Bill

[Robert]

Hi Bill,
the filter is working very well. The pump is even quieter now but the outflow is a bit smaller too. The filter is brownish now because of all the dirt and I didn't cleaned it yet. That reduces the flow-rate a bit of course. But I let it work like a HMF filter, so I don't have any intention to clean it if it is not necessary.

Best regards

Robert

[stcyrwm]

Robert,

Thanks for the quick response. I am glad to hear that it is working. What is the principle behind the "Hamburger Matten filter"? I went to the website but I can only read english so I couldn't read it. Specifically why are you waiting to clean it? I'm curious about cleaning it and how much of the debris would fall off as you pulled it out of the tank.
Also what size pump did you use and how did you size it. I think I'm going to be making one of these this week.

Thanks, Bill

[Robert]

Hi Bill,
the HMF is a biological filter, no mechanical one. The trick is to provide a huge surface and a slow water flow to make good conditions for aerobe bacteria to reduce the ammonia into nitrite and later on nitrate. If the water flow is too strong it won't work as well as if it is to slow. A pump which is able to pump twice the tank-volume thru the mat would be good. I use a 180l pump for my 86l tank. It works fine.

Behind the filter mat there should be some mulm, it works much better with mulm behind it. So you don't clean the filter nor the place behind it. My filter keeps the mulm inside on the ground of it. It is closed with the help of the stone, so even if I move it in the tank, I find only the mulm behind and around it.
Because of the slow water flow, you won't have much dirt directly in the mat but the brown stuff are bacteria. They can live for a very long time there, I heard of somebody who did not cleaned his HMF for 10 years! You can cover the front of the HMF with some moss or java fern as long as the flow rate is not affected. BTW, you always need some bioload in the tank or the bacteria will starve and die and the filter will become useless.

Mr. Deters can explain it much better than me. He did a lot of research on this topic. Use an online translators like http://www.systransoft.com/index.html or http://babelfish.altavista.digital.com/ to translate his whole website. It is the best source of knowledge about this kind of filter you can find. You can also calculate on his site the right size of the mat to get the best possible filtration.

Best regards

Robert

[livandlovit]

What is the principle behind the "Hamburger Matten filter"? I went to the website but I can only read english so I couldn't read it.
Thanks, Bill

Hi there,

I love the whole concept of this filter!

I have a link to a page that has the instructions in English for this Hamburg Matten filter. But for some reason this forum won't let me post a reply with the address in the text. The error message I get says that I cannot post my message because it contains a URL and as a new member I'm not allowed to include them. (I registered for this forum just so I could give you this link).
I've tried all different ways to "alter" the address so that it won't present as a URL but nothing is working, so this is my last resort! The link is

... triple w (dot) janrigter.nl (forwardslash) mattenfilter (forwardslash)

Whew!
www.janrigter.nl/mattenfilter

From,
livandlovit

[stcyrwm]

Thanks for the link. I have two tanks now that I filter with my own modified version of these biological filters. I simply use an HOB filter and put a sponge on the inlet side of the filter. I have one on a 10 gallon shrimp only and one on a 55 gallon shrimp/fish and both tanks stay as clear as my tanks with canister filters. I don't have to clean the filter except for occasionally scraping excess debris off the sponge.

Bill

[Robert]

Hi,
I use this filter for more than a half year now and I'm satisfied. I have very stable conditions (the best of all my tanks) and I have no trouble at all with the filter. I don't have to clean it and the flow-rate is very stable. I also set up a smaller version of this filter (with a tiny pump of approximately 3x3x2cm) in a 2ft tank and it works as good as the larger one.

The only disadvantage so far is that this filter needs a rather long time before it really works well. The bacteria need more than a month to colonise the whole mat. They need even more time in a tank with a low bioload . But when it is done, they do a pretty good job.

best regards
Robert

[Walter]

I would like to share a self made cotton/sponge filter which is done a similiar way but much simplier.

We can use a piece of filter cotton and wrap around an air stone (In anyway as long the entire stone is covered), then use a rubber band to tie the cotton onto the airstone. Later on, by running the airpump, we have a DIY sponge filter.

Works well for me. :D

[stcyrwm]

Walter,

How big of a tank/what type do you do this in? Do you clean the filter - how and how often? I love hearing about these little projects :D .

Thanks, Bill

[Walter]

I only use this DIY sponge filter on 1feet to 2feet tanks; Small tanks. As sponge filters arent for the big tanks anyway. :) This is rather good for me as I do not need to buy commercial sponge filters anymore as they work the same. :D

This is how they work, as the air stone is activated by a pump, the air bubbles will push water upwards, so the water at the sides will fill in the displaced water and this action (a current) passes through the cotton and up again, thus a filtration! :D