I had five minutes to spare and was bored. So I made a sponge filter. Here it is:


(Edited to add list of parts needed: Airpump, lift tube, airstone (optional), air tubing, fish food pot, gravel, filter floss/sponge).

Take a bog standard fish flake pot. Take the sticker off the outside. This plastic is guaranteed to be fish safe because obviously it is intended to store their food



Take a piece of tubing/hose about 1/2" - 1" diameter. Cut four little notches at the bottom (you can do this with a knife or saw).



Put the tubing down to the centre of the pot and pour gravel around it until about 3/4 of the pot is filled. DON'T lift the tube out at this point because you will have to then take all the gravel out and it is a right pain.



Now you can put some sponge or filter floss on top to act as mechanical filtration. One of those sponges attached to a scourer will do - if in doubt, look closely at the sponge. If you can see lots of little plastic fibres you're ok - if it is closed cell and rots over time (sponges made of cellulose) then DON'T use it - it will rot in your tank.



Here are all the bits so far. If you wanted you could get the lid and drill a hole for the lift tube and some smaller intake holes, but I couldn't be bothered because it is a 5 mintue sponge filter - that's what it is. I tried to make it as bare bones as possible.



Drill a hole the same or slightly smaller than the diameter of your airtubing and poke the airtubing through it.



If your tube is wide enough, add an airstone.



And there you have it - a perfectly acceptable five minute simple sponge filter for a hospital/quarantine tank. Here is my sponge filter in action, literally five minutes after the idea popped into my head:



Have fun!

This post has been edited by sammydee: Apr 6 2005, 02:37 PM

Look good.

That's great! Recycled fish food containers!

Tolak

MAybe a mod should move it to DIY section,

Great Idea

Suggestion though would it not also work without the large tube just bury the airstone in the gravel stick a sponge ontop and poke a couple small holes in the bottom

This post has been edited by vantgE: Apr 5 2005, 09:50 PM

It is more effective with the lift tube I think, but that wy would work with a very small container.

why is there one in diy and one here?

Oops I must have posted it in both. My bad. Could the mods get rid of this one then, if it is in DIY as well?

i think it should be pinned
very well done

DD

agreed...great idea

OK I was just fiddling round with the filter to see what I could improve and I cam up with a couple of ideas:

Firstly, your lift tube needs to be as thin as possible otherwise water will come down the lift tube and be sucked up instead of being sucked through the filter media. You could also add an inverted cone on top of a lift tube to stop this effect.

Secondly, with a thinner lift tube, to get an airstone to direct the bubble up it, you need to add an inverted cone shape at the bottom to funnel the bubbles up the tube. You could just leave the air tube bare with no stone but I think some of the effectiveness is lost this way.

With a reasonably powerful airpump I think you could achieve about 20-30GPH flow.