DIY Sponge filters...

[ciaong]

Hi everyone!
I plan on making a small fry/shrimp tank out of one of those terrarium habitat totes. (The kind that's basically a plastic box with a vented lid.) Since most filters seem too powerful for such a small setup, I was thinking of building a sponge filter(air-pump driven). I have a couple questions:
1) Is it necessary to punch holes in the uplift tube and where should they be? I've seen designs were the holes were above the sponge, below the sponge, and tubes where the only hole was for the airline tube.
2) How, exactly, would this produce enough aeration? I know that the pumped air is supposed to drive the water up, but wouldn't this only work with uplift ubes that closely match the width of the airline? Otherwise, wouldn't the air just bubble straight up to the surface?
Thanks for any advice/answers!

 

[Kasakato]

I thinks its best just to buy one. They are cheep, and they work well. http://www.bigalsonline.com/catalog/category.xml?pcid1=2885;category_id=1725

 

[toofazt]

To make holes in the sponge you just put the sponge in a container that is about the same size of the sponge. Put water in the container about an inch above the sponge. Put the container with the sponge/water in the freezer till it freezes. Take it out and you can now drill all the holes you need to in the sponge.

 

[Kasakato]

DIY is more likely more expensive than just buying one. But if you need one to me a special shape, or some that's really big, DIY is the way.

 

[Aderynglas]

If it's a really small tank and only lightly stocked you can make a sponge filter run by air pump out of an uplift tube and a piece of filter sponge (used sponge from a working filter is good in an emergency ) take a piece of uplift tube with a 'top' to it (the kind that Ug's come with) and cut to fit tank, cut a piece of sponge to fit inside the bottom of the tube, it can go up as far as half way if you want Fit airline tubing thru the 'top' and an airstone on the bottom of it as usual, put the 'top' back on the uplift and place in the tank securing to the tank with an old heater support thingy (that's the technical term I think) adjust the airpump or fit a valve to give correct flow and away you go, takes minutes to make

An improvement to the above is to put in a couple of ceramic noodles from a working filter for extra bio filtration

 

[daveedka]

Otherwise, wouldn't the air just bubble straight up to the surface?

Just for clarification, the upward movement of the bubbles creates waterflow, the annulus (sp) of the lift tube will effect the flow, but no matter what you will still get water flow.

How, exactly, would this produce enough aeration?

aereation is a result of surface disturbance, not the bubbles moving through the water. since the air must escape the tank it will disturb the surface and allow gas exchange. all it really has to do is break the surface.

dave

 

[bayoupr]

You could also hook a powerhead to your sponge. This works great for me. Moves a lot of water through the sponge. And as mentioned in a previous post you would be surprised how much mechanical filtration a sponge can do. The thing a like about sponge filters is how easy they are to clean.

 

[Aderynglas]

A POWERHEAD in a terrarium tote?? Now there's a scary thought